Alloy composition

Abstract

The present disclosure relates to an alloy composition. The alloy composition provides enhanced wear resistance, heat resistance, and corrosion resistance. The alloy composition provides excellent corrosion resistance in terms of Pitting Resistance Equivalent Number (PREN) values and Intergranular Corrosion B (IGC B) values. The alloy composition is used to make sinker rolls, stabilizer rolls, deflector rolls, and wiper rolls in cold roll galvanizing and galvalumes.

Description

[0001] ALLOY COMPOSITION

[0002] FIELD

[0003] The present disclosure relates to the field of metallurgy. Particularly, the present disclosure relates to an alloy composition.

[0004] DEFINITIONS

[0005] As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used, indicate otherwise.

[0006] Austenitic microstructure: The term “Austenitic microstructure” refers to a specific arrangement of atoms in steel and iron alloys, primarily found in a face-centred cubic (FCC) crystal structure. Austenitic microstructure is known for its superior mechanical properties and toughness.

[0007] Ferritic microstructure: The term “Ferritic microstructure” refers to a specific arrangement of atoms in steel and iron alloys, characterized by a body-centred cubic (BCC) crystal structure. Ferritic microstructure is relatively soft and weak compared to other microstructures.

[0008] Pitting Corrosion: The term “pitting corrosion” refers to a localized form of corrosion by which cavities or pits are produced in the material.

[0009] Pitting Resistance Equivalent Number (PREN): The term “Pitting Resistance Equivalent Number (PREN)” is a measure to estimate the resistance of stainless steels and other alloys to pitting corrosion. Higher PREN indicates better resistance to pitting corrosion, while lower PREN indicates poorer resistance to pitting corrosion.

[0010] Ferrite Number: The term “ferrite number” is a measure used to estimate the amount of ferrite present in stainless steel and welds, particularly in austenitic steels. The ferrite number helps to predict the behaviour of stainless steel. A lower ferrite number indicates better corrosion resistance.

[0011] IGC Practise B: The term “IGC Practice B” refers to a specific method used to assess the susceptibility of stainless steels to inter granular corrosion (IGC) in an austenitic stainless steel, mainly as a result of chromium depletion due to carbide precipitation. The test is performed by boiling the test piece in a 50% solution of ferric sulphate and sulphuric acid for 120 hours.

[0012] Sinker rolls: The term “sinker rolls” are used for crucial components used in various industrial processes, particularly in metal working and steel production industries in guiding and controlling the movement of materials.

[0013] Stabilizer rolls: The term “stabilizer roll” refers to the components used in various manufacturing and processing industries to control and stabilize the movement and positioning of materials. They help ensure consistent quality and precision in the final product

[0014] Deflector rolls: The term “deflector roll” refers to the components used in various industrial applications to guide, redirect, or support moving materials in metal processing. Deflector rolls are used as support rolls that guide the metal strip so that it enters at the correct angle and alignment. It also reduces flatness, waviness and edge drop, thus helping to maintain a uniform thickness of the material.

[0015] Wiper rolls: The term “wiper roll” refers to the components used to improve the surface quality by reducing roller marks on the materials by controlling the surface roughness and ensuring uniform lubrication, by removing excess liquid such as molten zinc and other coatings.

[0016] Dross: The term “dross” refers to the impurities and waste materials that form on the surface of molten metal during processes such as smelting, casting, or refining.

[0017] Alloy 316L: The term “316L alloy” or “AISI 316L stainless steel” refers to a type of austenitic stainless steel with excellent corrosion resistance. It contains chromium, nickel, and molybdenum, with low carbon content (less than 0.03%).

[0018] Alloy CF3M: The term “alloy CF3M” refers to austenitic stainless steel designed for castings used in pressure-containing parts. It has high chromium and molybdenum content, providing excellent corrosion resistance.

[0019] Schaeffler diagram: The term “Schaeffler diagram” refers to a graphical tool used in welding to predict the microstructure of stainless steel welds based on their chemical composition. It aids in determining the balance of different phases - such as austenite, ferrite, and martensite — in the weld deposit by evaluating the effects of nickel and chromium equivalents.

[0020] BACKGROUND

[0021] The background information herein below relates to the present disclosure but is not necessarily prior art.

[0022] Sinker rolls are critical components used in continuous hot-dip galvanizing lines. Their primary function is to guide and submerge steel sheets into molten zinc baths to obtain even coating and proper immersion. These rolls are typically made from corrosion-resistant materials, such as austenitic stainless steel alloys that have the ability to withstand the corrosive environment of the molten zinc and / or molten aluminium under elevated temperatures.

[0023] Stabilizer rolls are used in various industrial processes to stabilize, guide, and control the movement of sheets during processing, while they are undergoing the process of galvanization. Stabilizer rolls are usually made from corrosion-resistant materials, such as austenitic stainless steel alloys.

[0024] The use of sinker rolls, stabilizer rolls, deflector rolls, and wiper rolls requires an alloy capable of withstanding harsh conditions, with high heat resistance and corrosion resistance. Corrosion resistance is required due to the aggressive conditions that prevail under molten zinc and aluminium baths. Poor corrosion resistance will result in severe pitting of the part that can cause premature failure of the sinker roll and the stabilizer roll and excessive dross formation on the surface of the roll, which in turn severely deteriorates the surface finish of the galvanized steel sheet resulting in rejections.

[0025] Alloy 316L rolled / wrought product and CF3M cast product is known for its excellent corrosion resistance and good mechanical properties. It contains molybdenum, which enhances its resistance to pitting and crevice corrosion, particularly in chloride environments. However, despite these advantages, it contains a considerable amount of ferrite and is generally not preferred for use in sinker rolls in hot-dip galvanizing processes for high end applications, due to formation of dross that is highly detrimental to the surface finish of the sheets.

[0026] IN401276 discloses a bi-component hollow cylindrical blank component having a stainless steel alloy as a first alloy and a second cobalt alloy. Further, despite containing molybdenum, stainless steel undergoes pitting corrosion under aggressive molten baths of molten zinc and / or aluminium, and is found to be inadequate for applications that require extended life.

[0027] Therefore, there is felt a need for an alloy that can mitigate the aforesaid drawbacks and provides an alternate solution.

[0028] OBJECTS

[0029] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.

[0030] An object of the present disclosure is to ameliorate one or more problems of the background or to at least provide a useful alternative.

[0031] Another object of the present disclosure is to provide an alloy composition.

[0032] Y et another object of the present disclosure is to provide an alloy composition for a component.

[0033] Still another object of the present disclosure is to provide an alloy composition for producing a sinker roll, a stabilizer roll, a deflector roll, and a wiper roll.

[0034] Yet another object of the present disclosure is to provide an alloy composition with low or no ferritic microstructure.

[0035] Still another object of the present disclosure is to provide an alloy composition for use in highly corrosive environment.

[0036] Yet another object of the present disclosure is to provide an alloy that can withstand harsh conditions generated in molten zinc baths, aluminium baths, cold roll galvanizing mills and galvalumes.

[0037] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

[0038] SUMMARY

[0039] The present disclosure relates to an alloy composition. The alloy composition comprises chromium in an amount in the range of 17 mass% to 22 mass% with respect to the total mass of the alloy composition, nickel in an amount in the range of 13 mass% to 16 mass% with respect to the total mass of the alloy composition, molybdenum in an amount in the range of 3 mass% to 4 mass% with respect to the total mass of the alloy composition, silicon in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of the alloy composition, manganese in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of the alloy composition, nitrogen in an amount in the range of 0.2 mass% to 0.3 mass% with respect to the total mass of the alloy composition, carbon in an amount in the range of 0.01 mass% to 0.03 mass% with respect to the total mass of the alloy composition, yttrium in an amount in the range of 0.2 mass% to 1.2 mass% with respect to the total mass of the alloy composition, cerium in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of the alloy composition, and q. s. iron.

[0040] In an embodiment of the present disclosure, the alloy composition comprises vanadium, copper, niobium and tungsten in a combined amount of less than 0.5 mass%.

[0041] In an embodiment of the present disclosure, the alloy composition comprises sulphur in an amount in the range of 0.001 mass% to 0.01 mass% with respect to the total mass of the alloy composition.

[0042] In an embodiment of the present disclosure, the alloy composition comprises phosphorus in an amount in the range of 0.01 mass% to 0.02 mass% with respect to the total mass of the alloy composition.

[0043] In an embodiment of the present disclosure, the alloy composition is characterized by having 0 vol% to 4 vol% of ferritic microstructure and 96 vol% to 100 vol% of austenitic microstructure.

[0044] In an embodiment of the present disclosure, the alloy composition is characterized by a Pitting Resistance Equivalent Number (PREN) value in the range of 30.43 to 40.825; and an Intergranular Corrosion B (IGC B) value of less than 12.

[0045] In an embodiment of the present disclosure, the alloy comprises 19.7 mass% of chromium with respect to the total mass of the alloy composition, 14.6 mass% of nickel with respect to the total mass of the alloy composition, 3.68 mass% of molybdenum with respect to the total mass of the alloy composition, 1.3 mass% of silicon with respect to the total mass of the alloy composition, 1.0 mass% of manganese with respect to the total mass of the alloy composition, 0.24 mass% of nitrogen with respect to the total mass of the alloy composition, 0.023 mass% of carbon with respect to the total mass of the alloy composition, 0.8 mass% of yttrium with respect to the total mass of the alloy composition, 0.6 mass% of cerium with respect to the total mass of the alloy composition, 0.017 mass% of vanadium with respect to the total mass of the alloy composition, 0.32 mass% of copper with respect to the total mass of the alloy composition, 0.021 mass% of niobium with respect to the total mass of the alloy composition, 0.043 mass% of tungsten with respect to the total mass of the alloy composition, 0.008 mass% of sulphur with respect to the total mass of the alloy composition, 0.015 mass% of phosphorus with respect to the total mass of the alloy composition and q. s. iron.

[0046] In an embodiment of the present disclosure, the alloy composition comprises 20.1 mass% of chromium with respect to the total mass of the alloy composition, 14.2 mass% of nickel with respect to the total mass of the alloy composition, 3.7 mass% of molybdenum with respect to the total mass of the alloy composition, 1.0 mass% silicon with respect to the total mass of the alloy composition, 1.3 mass% of manganese with respect to the total mass of the alloy composition, 0.26 mass% of nitrogen with respect to the total mass of the alloy composition, 0.022 mass% of carbon with respect to the total mass of the alloy composition, 0.8 mass% of yttrium with respect to the total mass of the alloy composition, 0.6 mass% of cerium with respect to the total mass of the alloy composition, 0.011 mass% of vanadium with respect to the total mass of the alloy composition, 0.26 mass% of copper with respect to the total mass of the alloy composition, 0.016 mass% of niobium with respect to the total mass of the alloy composition, 0.04 mass% of tungsten with respect to the total mass of the alloy composition, 0.01 mass% of sulphur with respect to the total mass of the alloy composition, 0.02 mass% of phosphorus with respect to the total mass of the alloy composition, and q. s. iron.

[0047] In an embodiment of the present disclosure, the alloy composition comprises 19.36 mass% of chromium with respect to the total mass of the alloy composition, 14.37 mass% of nickel with respect to the total mass of the alloy composition, 3.9 mass% of molybdenum with respect to the total mass of the alloy composition, 1.1 mass% silicon with respect to the total mass of the alloy composition, 1.2 mass% of manganese with respect to the total mass of the alloy composition, 0.21 mass% of nitrogen with respect to the total mass of the alloy composition, 0.025 mass% of carbon with respect to the total mass of the alloy composition, 0.8 mass% of yttrium with respect to the total mass of the alloy composition, 0.6 mass% of cerium with respect to the total mass of the alloy composition, 0.016 mass% of vanadium with respect to the total mass of the alloy composition, 0.31 mass% of copper with respect to the total mass of the alloy composition, 0.022 mass% of niobium with respect to the total mass of the alloy composition, 0.041 mass% of tungsten with respect to the total mass of the alloy composition, 0.01 mass% of sulphur with respect to the total mass of the alloy composition, 0.02 mass% of phosphorus with respect to the total mass of the alloy composition, and q. s. iron.

[0048] In an embodiment of the present disclosure, the alloy composition comprises 20.3 mass% of chromium with respect to the total mass of the alloy composition, 14.13 mass% of nickel with respect to the total mass of the alloy composition, 3.2 mass% of molybdenum with respect to the total mass of the alloy composition, 1.4 mass% silicon with respect to the total mass of the alloy composition, 1.15 mass% of manganese with respect to the total mass of the alloy composition, 0.24 mass% of nitrogen with respect to the total mass of the alloy composition, 0.026 mass% of carbon with respect to the total mass of the alloy composition, 0.8 mass% of yttrium with respect to the total mass of the alloy composition, 0.6 mass% of cerium with respect to the total mass of the alloy composition, 0.019 mass% of vanadium with respect to the total mass of the alloy composition, 0.3 mass% of copper with respect to the total mass of the alloy composition, 0.011 mass% of niobium with respect to the total mass of the alloy composition, 0.038 mass% of tungsten with respect to the total mass of the alloy composition, 0.01 mass% of sulphur with respect to the total mass of the alloy composition, 0.02 mass% of phosphorus with respect to the total mass of the alloy composition, and q. s. iron.

[0049] In an embodiment of the present disclosure, a component selected from the group consisting of a sinker roll, a stabilizer roll, a wiper roll, and a deflector roll is cast from the alloy composition of the present disclosure.

[0050] In another aspect, the present disclosure relates to a process for the preparation of a sinker roll from the alloy composition. The process comprises the following steps: a) melting predetermined amounts of stainless steel alloy scrap, nitrated ferrochrome, low carbon ferrochrome, nickel, ferromolybdenum and ferrosilicon to obtain a melt; b) deoxidizing the melt followed by adding predetermined amounts of yttrium and cerium to obtain a resultant melt; c) deslagging the resultant melt to obtain an alloy composition; d) casting the alloy composition in two separate sand moulds followed by solidification to obtain two end flanges; e) separately casting the alloy composition in a pre-rotating centrifugal casting mould sufficient to generate a gravitational force in the range of 40 G to 55 G followed by solidification to obtain a cast pipe; and f) welding the end flanges to the cast pipe to obtain a sinker roll.

[0051] In an embodiment of the present disclosure, the alloy composition comprises: i. chromium in an amount in the range of 17 mass% to 22 mass% with respect to the total mass of the alloy composition; ii . nickel in an amount in the range of 13 mass% to 16 mass% with respect to the total mass of the alloy composition; iii. molybdenum in an amount in the range of 3 mass% to 4 mass% with respect to the total mass of the alloy composition; iv. silicon in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of the alloy composition; v. manganese in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of the alloy composition; vi. nitrogen in an amount in the range of 0.2 mass% to 0.3 mass% with respect to the total mass of the alloy composition; vii. carbon in an amount in the range of 0.01 mass% to 0.03 mass% with respect to the total mass of the alloy composition; viii. yttrium in an amount in the range of 0.2 mass% to 1.2 mass% with respect to the total mass of the alloy composition; ix. cerium in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of the alloy composition; x. vanadium, copper, niobium and tungsten in a combined amount of less than 0.5 mass% with respect to the total mass of the alloy composition; xi. sulphur in an amount in the range of 0.001 mass% to 0.01 mass% with respect to the total mass of the alloy composition; xii. phosphorus in an amount in the range of 0.01 mass% to 0.02 mass% with respect to the total mass of the alloy composition; and xiii. q. s. iron. In an embodiment of the present disclosure, the stainless steel alloy scrap is present in an amount in the range of 75 mass% to 90 mass% with respect to the total mass of the melt.

[0052] In an embodiment of the present disclosure, nitrated ferrochrome is present in an amount in the range of 1 mass% to 5 mass% with respect to the total mass of the melt.

[0053] In an embodiment of the present disclosure, low carbon ferrochrome is present in an amount in the range of 4 mass% to 10 mass% with respect to the total mass of the melt.

[0054] In an embodiment of the present disclosure, nickel is present in an amount in the range of 2 mass% to 8 mass% with respect to the total mass of the melt.

[0055] In an embodiment of the present disclosure, ferro molybdenum is present in an amount in the range of 1 mass% to 5 mass% with respect to the total mass of the melt.

[0056] In an embodiment of the present disclosure, ferro silicon is present in an amount in the range of 0.5 mass% to 3 mass% with respect to the total mass of the melt.

[0057] In an embodiment of the present disclosure, the melt is present in an amount in the range of 95 mass% to 99 mass% with respect to the total mass of the resultant melt.

[0058] In an embodiment of the present disclosure, yttrium is present in an amount in the range of 0.5 mass% to 1 mass% with respect to the total mass of the resultant melt.

[0059] In an embodiment of the present disclosure, cerium is present in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of the resultant melt.

[0060] DETAILED DESCRIPTION

[0061] The present disclosure relates to the field of metallurgy. Particularly, the present disclosure relates to an alloy composition.

[0062] Embodiments of the present disclosure will now be described herein.

[0063] Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

[0064] The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open-ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and / or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.

[0065] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed elements.

[0066] The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.

[0067] Sinker rolls, stabilizer rolls, deflector rolls, and wiper rolls are essential in continuous hot-dip galvanizing lines, guiding steel sheets into molten zinc baths for even coating. These rolls are typically made from corrosion-resistant materials, like austenitic stainless steel alloys, to withstand the corrosive environments of molten zinc and aluminium at elevated temperatures. The need for high heat and corrosion resistance is critical, as inadequate resistance can lead to premature failure, excessive dross formation, and poor surface finish on galvanized sheets. Although Alloy 316L and CF3M cast products are known for their corrosion resistance due to molybdenum, they are generally unsuitable for high-end applications in galvanizing processes. These alloys tend to form detrimental dross and suffer from pitting corrosion in aggressive molten baths, limiting their lifespan in such environments. Throughout the specification, the terms “alloy” and “alloy composition” are used interchangeably.

[0068] The present disclosure provides an alloy composition. Particularly, the present disclosure provides an alloy composition for producing component such as sinker roll, stabilizer roll, deflector roll, and wiper roll that is used in highly corrosive conditions such as cold roll galvanizing mills and galvalumes.

[0069] The present disclosure relates to an alloy composition. The alloy comprises chromium in an amount in the range of 17 mass% to 22 mass% with respect to the total mass of the alloy composition, nickel in an amount in the range of 13 mass% to 16 mass% with respect to the total mass of the alloy composition, molybdenum in an amount in the range of 3 mass% to 4 mass% with respect to the total mass of the alloy composition, silicon in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of the alloy composition, manganese in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of the alloy composition, nitrogen in an amount in the range of 0.2 mass% to 0.3 mass% with respect to the total mass of the alloy composition, carbon in an amount in the range of 0.01 mass% to 0.03 mass% with respect to the total mass of the alloy composition, yttrium in an amount in the range of 0.2 mass% to 1.2 mass% with respect to the total mass of the alloy composition, cerium in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of the alloy composition, and q. s. iron.

[0070] In an embodiment of the present disclosure, the alloy composition comprises vanadium, copper, niobium and tungsten in a combined amount of less than 0.5 mass% with respect to the total mass of the alloy composition. In an exemplary embodiment, the alloy composition comprises vanadium, copper, niobium and tungsten in a combined amount of less than 0.401 mass% with respect to the total mass of the alloy composition.

[0071] In an embodiment of the present disclosure, the alloy composition comprises sulphur in an amount in the range of 0.001 mass% to 0.01 mass%. In an exemplary embodiment, the alloy composition comprises 0.008 mass% sulphur with respect to the total mass of the alloy composition.

[0072] In an embodiment of the present disclosure, the alloy composition comprises phosphorus in an amount in the range of 0.01 mass% to 0.02 mass% with respect to the total mass of the alloy composition. In an exemplary embodiment, the alloy composition comprises 0.015 mass% phosphorus with respect to the total mass of the alloy composition.

[0073] In an embodiment of the present disclosure, the alloy composition comprises 19.7 mass% of chromium with respect to the total mass of the alloy composition, 14.6 mass% of nickel with respect to the total mass ofthe alloy composition, 3.68 mass% ofmolybdenum with respect to the total mass of the alloy composition, 1.3 mass% of silicon with respect to the total mass of the alloy composition, 1.0 mass% of manganese with respect to the total mass of the alloy composition, 0.24 mass% of nitrogen with respect to the total mass of the alloy composition, 0.023 mass% of carbon with respect to the total mass of the alloy composition, 0.8 mass% of yttrium with respect to the total mass of the alloy composition, 0.6 mass% of cerium with respect to the total mass ofthe alloy composition, 0.017 mass% of vanadium with respect to the total mass of the alloy composition, 0.32 mass% of copper with respect to the total mass of the alloy composition, 0.021 mass% of niobium with respect to the total mass of the alloy composition, 0.043 mass% of tungsten with respect to the total mass of the alloy composition, 0.008 mass% sulphur with respect to the total mass of the alloy composition, 0.015 mass% phosphorus with respect to the total mass of the alloy composition, and q. s. iron.

[0074] In an embodiment of the present disclosure, the alloy composition comprises 20.1 mass% of chromium with respect to the total mass of the alloy composition, 14.2 mass% of nickel with respect to the total mass of the alloy composition, 3.7 mass% of molybdenum with respect to the total mass of the alloy composition, 1.0 mass% silicon with respect to the total mass of the alloy composition, 1.3 mass% of manganese with respect to the total mass of the alloy composition, 0.26 mass% of nitrogen with respect to the total mass of the alloy composition, 0.022 mass% of carbon with respect to the total mass of the alloy composition, 0.8 mass% of yttrium with respect to the total mass of the alloy composition, 0.6 mass% of cerium with respect to the total mass of the alloy composition, 0.011 mass% of vanadium with respect to the total mass of the alloy composition, 0.26 mass% of copper with respect to the total mass of the alloy composition, 0.016 mass% of niobium with respect to the total mass of the alloy composition, 0.04 mass% of tungsten with respect to the total mass of the alloy composition, 0.01 mass% of sulphur with respect to the total mass of the alloy composition, 0.02 mass% of phosphorus with respect to the total mass of the alloy composition, and q. s. iron. In an embodiment of the present disclosure, the alloy composition comprises 19.36 mass% of chromium with respect to the total mass of the alloy composition, 14.37 mass% of nickel with respect to the total mass of the alloy composition, 3.9 mass% of molybdenum with respect to the total mass of the alloy composition, 1.1 mass% silicon with respect to the total mass of the alloy composition, 1.2 mass% of manganese with respect to the total mass of the alloy composition, 0.21 mass% of nitrogen with respect to the total mass of the alloy composition, 0.025 mass% of carbon with respect to the total mass of the alloy composition, 0.8 mass% of yttrium with respect to the total mass of the alloy composition, 0.6 mass% of cerium with respect to the total mass of the alloy composition, 0.016 mass% of vanadium with respect to the total mass of the alloy composition, 0.31 mass% of copper with respect to the total mass of the alloy composition, 0.022 mass% of niobium with respect to the total mass of the alloy composition, 0.041 mass% of tungsten with respect to the total mass of the alloy composition, 0.01 mass% of sulphur with respect to the total mass of the alloy composition, 0.02 mass% of phosphorus with respect to the total mass of the alloy composition, and q. s. iron.

[0075] In an embodiment of the present disclosure, the alloy composition comprises 20.3 mass% of chromium with respect to the total mass of the alloy composition, 14.13 mass% of nickel with respect to the total mass of the alloy composition, 3.2 mass% of molybdenum with respect to the total mass of the alloy composition, 1.4 mass% silicon with respect to the total mass of the alloy composition, 1.15 mass% of manganese with respect to the total mass of the alloy composition, 0.24 mass% of nitrogen with respect to the total mass of the alloy composition, 0.026 mass% of carbon with respect to the total mass of the alloy composition, 0.8 mass% of yttrium with respect to the total mass of the alloy composition, 0.6 mass% of cerium with respect to the total mass of the alloy composition, 0.019 mass% of vanadium with respect to the total mass of the alloy composition, 0.3 mass% of copper with respect to the total mass of the alloy composition, 0.011 mass% of niobium with respect to the total mass of the alloy composition, 0.038 mass% of tungsten with respect to the total mass of the alloy composition, 0.01 mass% of sulphur with respect to the total mass of the alloy composition, 0.02 mass% of phosphorus with respect to the total mass of the alloy composition, and q. s. iron.

[0076] In one embodiment of the present disclosure, the alloy may contain additional impurities that are commonly known in the field of metallurgy. In an embodiment of the present disclosure, the alloy is having 0 vol% to 4 vol% of ferritic microstructure and 96 vol% to 100 vol% of austenitic microstructure.

[0077] In an embodiment of the present disclosure, the amount of the ferrite in the alloy is calculated by using a Schaeffler diagram. In an exemplary embodiment, the alloy is having 0 vol% of ferritic microstructure and 100 vol% of austenitic microstructure. In another exemplary embodiment, the alloy is having 1 vol% ferritic microstructure and 99 vol% of austenitic microstructure.

[0078] The higher amount of austenite stabilizer such as nickel and manganese and lower amount of other ferrite formers provide an alloy that is free of ferrite content.

[0079] The addition of nitrogen helps to improve the issues of cracks, provides pitting resistance to the alloy, reduces pitting corrosion and also provides adequate strength to withstand the centrifugal stress and prevent cracking.

[0080] In an embodiment of the present disclosure, the alloy composition is characterized by a Pitting Resistance Equivalent Number (PREN) value in the range of 30.43 to 40.825. In an exemplary embodiment, the alloy composition is characterized by a Pitting Resistance Equivalent Number (PREN) value of 36.3935. In another exemplary embodiment, the alloy composition is characterized by a Pitting Resistance Equivalent Number (PREN) value of 37. 13. In yet another exemplary embodiment, the alloy composition is characterized by a Pitting Resistance Equivalent Number (PREN) value of 36.2665. In still another exemplary embodiment, the alloy composition is characterized by a Pitting Resistance Equivalent Number (PREN) value of 35.327.

[0081] The Pitting Resistance Equivalent Number (PREN) is a generally used as a parameter for evaluating the corrosion resistance of stainless steels, especially against pitting corrosion. Pitting corrosion is a localized form of corrosion that leads to the creation of small holes or pits in the material, often in the presence of chloride ions. The most commonly used formula for PREN is:

[0082] PREN = %Cr + 3.3 x %Mo + 16 x %N

[0083] For more accurate predictions, especially in high-alloy stainless steels, an extended formula includes tungsten (W): PREN = %Cr + 3.3 x (%Mo + 0.5 x %W) + 16 x %N

[0084] Chromium (Cr), molybdenum (Mo), and nitrogen (N) are the primary elements contributing to pitting resistance. Chromium provides general corrosion resistance, molybdenum enhances the pitting resistance, and nitrogen improves both pitting resistance and strength.

[0085] In an embodiment of the present disclosure, the alloy composition is characterized by an Intergranular Corrosion B (IGC B) value of less than 12. In an exemplary embodiment, the Intergranular Corrosion B (IGC B) value is 9.3469. In another exemplary embodiment, the Intergranular Corrosion B (IGC B) value is 6.3294. In still another exemplary embodiment, the Intergranular Corrosion B (IGC B) value is 8.2214. In yet another exemplary embodiment, the Intergranular Corrosion B (IGC B) value is 11.9280.

[0086] The presence of chromium in the alloy composition confers oxidation resistance, nickel acts as a strong austenitizer and imparts toughness. Molybdenum offers resistance against pitting corrosion that can occur in molten metal baths. Manganese is a primary deoxidizer and also works as an austenitizer. Nitrogen acts as a strong austenitizer and increases alloy strength. The addition of rare earth elements reduces the creep damage of the alloy and also reduces the propensity to cracking. Silicon improves oxidation resistance, it can also enhance the alloy's resistance to certain types of corrosion, particularly in acidic environments.

[0087] Copper, vanadium and niobium are present as trace elements. Tungsten increases high- temperature strength and hardness of the alloy and also increases the pitting resistance. Chromium, nickel, molybdenum and nitrogen help to provide the IGC B properties. Cerium and yttrium further improve the same.

[0088] In an embodiment of the present disclosure, a component selected from the group consisting of a sinker roll, a stabilizer roll, a wiper roll, and a deflector roll is cast from the alloy composition of the present disclosure. In an exemplary embodiment, the component is a sinker roll.

[0089] In another aspect, the present disclosure relates to a process for the preparation of a sinker roll from the alloy composition. The process comprises the steps of melting predetermined amounts of stainless steel alloy scrap, nitrated ferrochrome, low carbon ferrochrome, nickel, ferromolybdenum and ferrosilicon to obtain a melt. The melt is deoxidized followed by adding predetermined amounts of yttrium and cerium to obtain a resultant melt. The resultant melt is deslagged to obtain an alloy composition. The alloy composition is casted in two separate sand moulds followed by solidification to obtain two end flanges. Separately, the alloy composition is casted in a pre-rotating centrifugal casting mould sufficient to generate a gravitational force in the range of 40 G to 55 G followed by solidification to obtain a cast pipe. The end flanges are welded to the cast pipe to obtain a sinker roll.

[0090] The process is described in detail.

[0091] In a first step, predetermined amounts of stainless steel alloy scrap, nitrated ferrochrome, low carbon ferrochrome, nickel, ferromolybdenum and ferrosilicon are melted to obtain a melt.

[0092] In an embodiment of the present disclosure, the stainless steel alloy scrap is present in an amount in the range of 75 mass% to 90 mass% with respect to the total mass of the melt. In an exemplary embodiment, the stainless steel alloy scrap is present in an amount of 82 mass% with respect to the total mass of the melt.

[0093] In an embodiment of the present disclosure, nitrated ferrochrome is present in an amount in the range of 1 mass% to 5 mass% with respect to the total mass of the melt. In an exemplary embodiment, the nitrated ferrochrome is present in an amount of 2.75 mass% with respect to the total mass of the melt.

[0094] In an embodiment of the present disclosure, low carbon ferrochrome is present in an amount in the range of 4 mass% to 10 mass% with respect to the total mass of the melt. In an exemplary embodiment, the low carbon ferrochrome is present in an amount of 6.8 mass% with respect to the total mass of the melt.

[0095] In an embodiment of the present disclosure, nickel is present in an amount in the range of 2 mass% to 8 mass% with respect to the total mass of the melt. In an exemplary embodiment, nickel is present in an amount of 4.2 mass% with respect to the total mass of the melt.

[0096] In an embodiment of the present disclosure, ferro molybdenum is present in an amount in the range of 1 mass% to 5 mass% with respect to the total mass of the melt. In an exemplary embodiment, ferro molybdenum is present in an amount of 2.8 mass% with respect to the total mass of the melt.

[0097] In an embodiment of the present disclosure, ferro silicon is present in an amount in the range of 0.5 mass% to 3 mass% with respect to the total mass of the melt. In an exemplary embodiment, ferro silicon is present in an amount of 1.45 mass% with respect to the total mass of the melt.

[0098] In a second step, the melt is deoxidized followed by adding predetermined amounts of yttrium and cerium to obtain a resultant melt.

[0099] In an embodiment of the present disclosure, the melt is present in an amount in the range of 95 mass% to 99 mass% with respect to the total mass of the resultant melt. In an exemplary embodiment, the melt is present in an amount of 98.6 mass% with respect to the total mass of the resultant melt.

[0100] In an embodiment of the present disclosure, yttrium is present in an amount in the range of 0.5 mass% to 1 mass% with respect to the total mass of the resultant melt. In an exemplary embodiment, yttrium is present in an amount of 0.79 mass% with respect to the total mass of the resultant melt.

[0101] In an embodiment of the present disclosure, cerium is present in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of the resultant melt. In an exemplary embodiment, cerium is present in an amount of 0.59 mass% with respect to the total mass of the resultant melt.

[0102] In a third step, the resultant melt is deslagged to obtain an alloy composition.

[0103] In an embodiment of the present disclosure, the alloy composition comprises: i . chromium in an amount in the range of 17 mass% to 22 mass% with respect to the total mass of the alloy composition; ii. nickel in an amount in the range of 13 mass% to 16 mass% with respect to the total mass of the alloy composition; iii. molybdenum in an amount in the range of 3 mass% to 4 mass% with respect to the total mass of the alloy composition; iv. silicon in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of the alloy composition; v. manganese in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of the alloy composition; vi. nitrogen in an amount in the range of 0.2 mass% to 0.3 mass% with respect to the total mass of the alloy composition; vii . carbon in an amount in the range of 0.01 mass% to 0.03 mass% with respect to the total mass of the alloy composition; viii. yttrium in an amount in the range of 0.2 mass% to 1.2 mass% with respect to the total mass of the alloy composition; ix. cerium in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of the alloy composition; x. vanadium, copper, niobium and tungsten in a combined amount of less than 0.5 mass% with respect to the total mass of the alloy composition; xi. sulphur in an amount in the range of 0.001 mass% to 0.01 mass% with respect to the total mass of the alloy composition; xii. phosphorus in an amount in the range of 0.01 mass%to 0.02 mass% with respect to the total mass of the alloy composition; and xiii. q. s. iron.

[0104] In an embodiment of the present disclosure, the stainless steel alloy scrap is present in an amount in the range of 75 mass% to 90 mass% with respect to the total mass of the melt.

[0105] In an embodiment of the present disclosure, nitrated ferrochrome is present in an amount in the range of 1 mass% to 5 mass% with respect to the total mass of the melt.

[0106] In an embodiment of the present disclosure, low carbon ferrochrome is present in an amount in the range of 4 mass% to 10 mass% with respect to the total mass of the melt.

[0107] In an embodiment of the present disclosure, nickel is present in an amount in the range of 2 mass% to 8 mass% with respect to the total mass of the melt.

[0108] In an embodiment of the present disclosure, ferro molybdenum is present in an amount in the range of 1 mass% to 5 mass% with respect to the total mass of the melt.

[0109] In an embodiment of the present disclosure, ferro silicon is present in an amount in the range of 0.5 mass% to 3 mass% with respect to the total mass of the melt.

[0110] In an embodiment of the present disclosure, the melt is present in an amount in the range of 95 mass% to 99 mass% with respect to the total mass of the resultant melt.

[0111] In an embodiment of the present disclosure, yttrium is present in an amount in the range of 0.5 mass% to 1 mass% with respect to the total mass of the resultant melt. In an embodiment of the present disclosure, cerium is present in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of the resultant melt.

[0112] In a fourth step, the alloy composition is casted in two separate sand moulds followed by solidification to obtain two end flanges.

[0113] In a fifth step, separately the alloy composition is casted in a pre-rotating centrifugal casting mould sufficient to generate a gravitational force in the range of 40 G to 55 G followed by solidification to obtain a cast pipe.

[0114] In an exemplary embodiment, the gravitational force is 50 G.

[0115] In a final step, the end flanges are welded to the cast pipe to obtain a sinker roll.

[0116] In an embodiment, the sinker roll is prepared by separately casting a barrel and two end flanges and welding the end flanges to either ends of the barrel. The barrel is casted / produced by conventional centrifugal casting, whereas the end flanges are casted / produced by conventional no bake sand moulding process.

[0117] In an embodiment, predetermined amounts of stainless steel alloy scrap, nitrated ferro chrome, low carbon ferro chrome, pure nickel, ferro molybdenum, and ferro silicon are melted in a furnace to obtain a pure melt. The so obtained melt is deoxidized, and predetermined amounts of yttrium and cerium are added to the melt to obtain a resultant melt. The resultant melt is tapped into a ladle at the desired superheated temperature. The resultant melt is deslagged to obtain an alloy composition and moved to a sand-casting pouring bay, followed by pouring the alloy composition into two sand moulds of the end flanges. After solidification the sand castings are knocked out, cleaned, ground, heat treated and machined as per the desired shape to obtain two end flanges. Separately, the ladle is moved onwards and the alloy composition is poured into pre-prepared and pre-rotating centrifugal casting metallic mould to obtain a cast pipe. After solidification the casted pipe is extracted, heat treated and machined to the final dimensions. The so obtained end flanges are welded to the so obtained cast pipe, under an argon cover to obtain the sinker roll assembly. The sinker roll assembly is balanced and finished to obtain the sinker roll.

[0118] The alloy composition of the present disclosure shows high pitting resistance equivalent number (PREN), low IGC (B) value and low ferrite number. The alloy composition of the present disclosure exhibits excellent corrosion resistance and advantageous mechanical properties suitable for use in the desired applications such as for the production of sinker rolls, stabilizer rolls, wiper rolls, and deflector rolls. The alloy composition exhibits superior resistance to fatigue, which is critical for components like sinker rolls, stabilizer rolls, wiper rolls, and deflector rolls that experience repeated stress cycles during operation. This reduces the risk of crack initiation and propagation, thereby extending the service life of the components.

[0119] The low ferrite number in the alloy composition contributes to a more uniform and tougher microstructure, which enhances its wear resistance. This is particularly beneficial in applications where the rolls are subject to constant friction and abrasion, leading to less material loss and maintaining dimensional stability overtime.

[0120] The alloy's corrosion resistance, strength, and durability give components a much longer lifespan. This reduces the frequency of replacements and maintenance, resulting in substantial cost savings over the operational life of the equipment.

[0121] The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment but are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.

[0122] The present disclosure is further described in light of the following examples which are set forth for illustration purpose only and are not to be construed for limiting the scope of the disclosure. The following examples can be scaled up to industrial / commercial scale and the results obtained can be extrapolated to industrial scale.

[0123] Examples and studies:

[0124] Example 1: Preparation of a sinker roll in accordance with the present disclosure:

[0125] A sinker roll was prepared by separately casting a barrel and two end flanges and welding the end flanges to either ends of the barrel. The barrel was casted by / produced by conventional centrifugal casting, whereas the end flanges were casted by / produced by conventional no bake sand moulding process.

[0126] 1640 Kg of 1.4435 stainless steel alloy scrap (AOD refined low sulphur scrap), 55 Kg of nitrated ferro chrome, 136 Kg of low carbon ferro chrome, 84 Kg of pure nickel, 56 Kg of ferro molybdenum, and 29 Kg of ferro silicon (total metal scrap of around 2000 kgs) were melted in an induction furnace to obtain a pure melt having low or nil ferrite content.

[0127] The so obtained melt was deoxidized, and 16 Kg of yttrium and 12 Kg of cerium were added to the melt to obtain a resultant melt. The resultant melt was tapped into a ladle at the desired superheated temperature, with the help of an EOT crane attached to a molten metal weigh scale.

[0128] The resultant melt was deslagged to obtain an alloy composition and the alloy composition was moved to a sand-casting pouring bay, followed by pouring the desired quantity of the alloy composition into two sand moulds of the end flanges. After solidification the sand castings were knocked out, fettled, ground, heat treated and machined as per the desired shape to obtain two end flanges.

[0129] Separately, the ladle was moved onwards to a pouring station of the centrifugal casting of the barrel. The desired quantity of the alloy composition metal was poured into pre-prepared and pre-rotating centrifugal casting metallic mould at a gravitational force of 50 G to obtain a cast pipe. Any excess quantity of the alloy composition was poured into a pre-prepared ‘pig’ sand box for remelting in the next campaign. After solidification, the centrifugally casted cast pipe was extracted, heat treated and machined to the final dimensions.

[0130] The so obtained end flanges were welded to the so obtained cast pipe, using specially formulated low ferrite welding electrodes under argon cover to obtain a sinker roll assembly. The assembly was balanced and inspected to obtain a finished sinker roll.

[0131] Examples 2 to 4:

[0132] Examples 2 to 4 were prepared in a similar manner to Example 1, except by varying the amount of alloy components so as to obtain an alloy composition, as illustrated in Table 1. Table 1 : Preparation of the alloy composition by varying the alloying components.

[0133] ♦the alloy composition of Example 1 contains 0.008 mass% sulphur and 0.015 mass% phosphorus; and

[0134] ** the alloy composition of Examples 2, 3 and 4 contain 0.01 mass% sulphur and 0.02 mass% phosphorus.

[0135] Corrosion studies

[0136] The Inter granular Corrosion (IGC) test were carried out for sinker rolls obtained in Examples 1 to 4. The results of an Inter granular Corrosion (IGC) test, (ASTM A262 Practice B test) were used to assess the susceptibility of stainless steels to inter granular corrosion, which can occur along the grain boundaries of metals. The acceptance criteria for a satisfactory IGC B test result is, a corrosion rate of less than 60 mils per year (my). This threshold indicates that the material has acceptable resistance to inter granular corrosion and is unlikely to suffer from significant degradation in service. The IGC B test results of the sinker rolls obtained in Example 1 to Example 4 were 9.3469 mpy, 6.3294 mpy, 8.2214 mpy, and 11.9280 mpy respectively. These results were well within the limit, implying that the materials demonstrated good resistance to inter granular corrosion.

[0137] Pitting Resistance Equivalent Number (PREN) studies

[0138] PREN is a valuable indicator of an alloy's ability to resist pitting corrosion, which is a localized form of corrosion that leads to the formation of small pits on the metal surface. This is particularly important for applications in marine environments, chemical processing, and other settings where chloride exposure is common. PREN is often used as a criterion for selecting materials for specific applications. A higher PREN value generally indicates better resistance to pitting. The sinker rolls obtained in Examples 1 to 4 were subjected to PREN studies.

[0139] Table 1 demonstrates that the addition of the specific amounts of Ni and Mo significantly enhanced the Pitting Resistance Equivalent Number (PREN). The PREN values for Examples 1 to 4 ranged from 35.327 to 37.13, indicating superior pitting resistance. In contrast, the comparative Examples 1 and 2 (IN401276) exhibited lower PREN values compared to the alloy compositions in accordance with the present disclosure.

[0140] The sinker rolls thus produced in accordance with process the present disclosure, using the alloy composition of the present disclosure, provides outstanding corrosion resistance, superior to that of the sinker rolls produced by the conventional process using the alloy composition of Comparative Examples 1 and 2. This enhanced corrosion resistance achieved for the sinker roll of the present disclosure (prepared by using the alloy composition of the present disclosure) is evidenced by the extended operational life of the sinker rolls and, more critically, by the consistently stain-free, aesthetically superior surface finish of the galvanized sheet product obtained by using the sinker roll of the present disclosure. The improvement in surface quality of the galvanized sheet is attributed to the substantial reduction in dross formation, a common issue with conventional sinker rolls, thereby validating the synergistic effect of the disclosed alloy composition and casting methodology of the present disclosure.

[0141] TECHNICAL ADVANCEMENTS

[0142] The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of:

[0143] - an alloy composition, that

[0144] • is used in harsh corrosive conditions used in molten zinc baths, aluminium baths, cold roll galvanizing and galvalumes; and

[0145] • provides an improved resistance to pitting corrosion.

[0146] Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising, will be understood to imply the inclusion of a stated element, integer or step,” or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0147] The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention. The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary. While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Claims

CLAIMS:

1. An alloy composition comprising: i. chromium in an amount in the range of 17 mass% to 22 mass% with respect to the total mass of said alloy composition; ii . nickel in an amount in the range of 13 mass% to 16 mass% with respect to the total mass of said alloy composition; iii. molybdenum in an amount in the range of 3 mass% to 4 mass% with respect to the total mass of said alloy composition; iv. silicon in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of said alloy composition; v. manganese in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of said alloy composition; vi. nitrogen in an amount in the range of 0.2 mass% to 0.3 mass% with respect to the total mass of said alloy composition; vii. carbon in an amount in the range of 0.01 mass% to 0.03 mass% with respect to the total mass of said alloy composition; viii. yttrium in an amount in the range of 0.2 mass% to 1.2 mass% with respect to the total mass of said alloy composition; ix. cerium in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of said alloy composition; and x. q. s. iron.

2. The alloy composition as claimed in claim 1, wherein said alloy composition comprises vanadium, copper, niobium and tungsten in a combined amount of less than 0.5 mass% with respect to the total mass of said alloy composition.

3. The alloy composition as claimed in claim 1 , wherein said alloy composition comprises sulphur in an amount in the range of 0.001 mass% to 0.01 mass% with respect to the total mass of said alloy composition.

4. The alloy composition as claimed in claim 1, wherein said alloy composition comprises phosphorus in an amount in the range of 0.01 mass% to 0.02 mass% with respect to the total mass of said alloy composition.

5. The alloy composition as claimed in claim 1 is characterized by having 0 vol% to 4 vol% of ferritic microstructure and 96 vol% to 100 vol% of austenitic microstructure.

6. The alloy composition as claimed in claim 1 is characterized by• a Pitting Resistance Equivalent Number (PREN) value in the range of 30.43 to 40.825; and• an Intergranular Corrosion B (IGC B) value less than 12.

7. The alloy composition as claimed in claims 1 to 4, wherein said alloy composition comprises:I. 19.7 mass% of chromium with respect to the total mass of said alloy composition;II. 14.6 mass% of nickel with respect to the total mass of said alloy composition;III. 3.68 mass% of molybdenum with respect to the total mass of said alloy composition;IV. 1.3 mass% silicon with respect to the total mass of said alloy composition;V. 1.0 mass% of manganese with respect to the total mass of said alloy composition;VI. 0.24 mass% of nitrogen with respect to the total mass of said alloy composition;VII. 0.023 mass% of carbon with respect to the total mass of said alloy composition;VIII. 0.8 mass% of yttrium with respect to the total mass of said alloy composition;IX. 0.6 mass% of cerium with respect to the total mass of said alloy composition;X. 0.017 mass% of vanadium with respect to the total mass of said alloy composition;XI. 0.32 mass% of copper with respect to the total mass of said alloy composition;XII. 0.021 mass% of niobium with respect to the total mass of said alloy composition;XIII. 0.043 mass% of tungsten with respect to the total mass of said alloy composition;XIV. 0.008 mass% of sulphur with respect to the total mass of said alloy composition;XV. 0.015 mass% of phosphorus with respect to the total mass of said alloy composition; andXVI. q. s. iron.

8. The alloy composition as claimed in claims 1 to 4, wherein said alloy composition comprises:I. 20.1 mass% of chromium with respect to the total mass of said alloy composition;II. 14.2 mass% of nickel with respect to the total mass of said alloy composition;III. 3.7 mass% of molybdenum with respect to the total mass of said alloy composition;IV. 1.0 mass% silicon with respect to the total mass of said alloy composition;V. 1.3 mass% of manganese with respect to the total mass of said alloy composition;VI. 0.26 mass% of nitrogen with respect to the total mass of said alloy composition;VII. 0.022 mass% of carbon with respect to the total mass of said alloy composition;VIII. 0.8 mass% of yttrium with respect to the total mass of said alloy composition;IX. 0.6 mass% of cerium with respect to the total mass of said alloy composition;X. 0.011 mass% of vanadium with respect to the total mass of said alloy composition;XI. 0.26 mass% of copper with respect to the total mass of said alloy composition;XII. 0.016 mass% of niobium with respect to the total mass of said alloy composition;XIII. 0.04 mass% of tungsten with respect to the total mass of said alloy composition;XIV. 0.01 mass% of sulphur with respect to the total mass of said alloy composition;XV. 0.02 mass% of phosphorus with respect to the total mass of said alloy composition; andXVI. q. s. iron.

9. The alloy composition as claimed in claims 1 to 4, wherein said alloy composition comprises:I. 19.36 mass% of chromium with respect to the total mass of said alloy composition;II. 14.37 mass% of nickel with respect to the total mass of said alloy composition;III. 3.9 mass% of molybdenum with respect to the total mass of said alloy composition;IV. 1.1 mass% silicon with respect to the total mass of said alloy composition;V. 1.2 mass% of manganese with respect to the total mass of said alloy composition;VI. 0.21 mass% of nitrogen with respect to the total mass of said alloy composition;VII. 0.025 mass% of carbon with respect to the total mass of said alloy composition;VIII. 0.8 mass% of yttrium with respect to the total mass of said alloy composition;IX. 0.6 mass% of cerium with respect to the total mass of said alloy composition;X. 0.016 mass% of vanadium with respect to the total mass of said alloy composition;XI. 0.31 mass% of copper with respect to the total mass of said alloy composition;XII. 0.022 mass% of niobium with respect to the total mass of said alloy composition;XIII. 0.041 mass% of tungsten with respect to the total mass of said alloy composition;XIV. 0.01 mass% of sulphur with respect to the total mass of said alloy composition;XV. 0.02 mass% of phosphorus with respect to the total mass of said alloy composition; andXVI. q. s. iron.

10. The alloy composition as claimed in claims 1 to 4, wherein said alloy composition comprises:I. 20.3 mass% of chromium with respect to the total mass of said alloy composition;II . 14.13 mass% of nickel with respect to the total mass of said alloy composition;III. 3.2 mass% of molybdenum with respect to the total mass of said alloy composition;IV. 1.4 mass% silicon with respect to the total mass of said alloy composition;V. 1.15 mass% of manganese with respect to the total mass of said alloy composition;VI. 0.24 mass% of nitrogen with respect to the total mass of said alloy composition;VII. 0.026 mass% of carbon with respect to the total mass of said alloy composition;VIII. 0.8 mass% of yttrium with respect to the total mass of said alloy composition;IX. 0.6 mass% of cerium with respect to the total mass of said alloy composition;X. 0.019 mass% of vanadium with respect to the total mass of said alloy composition;XI. 0.3 mass% of copper with respect to the total mass of said alloy composition;XII. 0.011 mass% of niobium with respect to the total mass of said alloy composition;XIII. 0.038 mass% of tungsten with respect to the total mass of said alloy composition;XIV. 0.01 mass% of sulphur with respect to the total mass of said alloy composition;XV. 0.02 mass% of phosphorus with respect to the total mass of said alloy composition; andXVI. q. s. iron.

11. A component selected from the group consisting of a sinker roll, a stabilizer roll, a wiper roll, and a deflector roll cast from the alloy composition as claimed in any of the claims 1 to 10.

12. A process for the preparation of a sinker roll from an alloy composition, said process comprising the following steps: a) melting predetermined amounts of stainless steel alloy scrap, nitrated ferrochrome, low carbon ferrochrome, nickel, ferromolybdenum and ferrosilicon to obtain a melt; b) deoxidizing said melt followed by adding predetermined amounts of yttrium and cerium to obtain a resultant melt; c) deslagging said resultant melt to obtain an alloy composition; d) casting said alloy composition in two separate sand moulds followed by solidification to obtain two end flanges;e) separately casting said alloy composition in a pre-rotating centrifugal casting mould sufficient to generate a gravitational force in the range of 40 G to 55 G followed by solidification to obtain a cast pipe; and f) welding said end flanges to said cast pipe to obtain a sinker roll.

13. The process as claimed in claim 12, wherein said alloy composition comprises: i. chromium in an amount in the range of 17 mass% to 22 mass% with respect to the total mass of said alloy composition; ii. nickel in an amount in the range of 13 mass% to 16 mass% with respect to the total mass of said alloy composition; iii . molybdenum in an amount in the range of 3 mass% to 4 mass% with respect to the total mass of said alloy composition; iv. silicon in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of said alloy composition; v. manganese in an amount in the range of 0.25 mass% to 1.5 mass% with respect to the total mass of said alloy composition; vi. nitrogen in an amount in the range of 0.2 mass% to 0.3 mass% with respect to the total mass of said alloy composition; vii. carbon in an amount in the range of 0.01 mass% to 0.03 mass% with respect to the total mass of said alloy composition; viii. yttrium in an amount in the range of 0.2 mass% to 1.2 mass% with respect to the total mass of said alloy composition; ix. cerium in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of said alloy composition; x. vanadium, copper, niobium and tungsten in a combined amount of less than 0.5 mass% with respect to the total mass of said alloy composition; xi. sulphur in an amount in the range of 0.001 mass% to 0.01 mass% with respect to the total mass of said alloy composition; xii. phosphorus in an amount in the range of 0.01 mass% to 0.02 mass% with respect to the total mass of said alloy composition; and xiii. q. s. iron.

14. The process as claimed in claim 12, wherein• said stainless steel alloy scrap is present in an amount in the range of 75 mass% to 90 mass% with respect to the total mass of said melt;• nitrated ferrochrome is present in an amount in the range of 1 mass% to 5 mass% with respect to the total mass of said melt;• low carbon ferrochrome ferrochrome is present in an amount in the range of 4 mass% to 10 mass% with respect to the total mass of said melt;• nickel is present in an amount in the range of 2 mass% to 8 mass% with respect to the total mass of said melt;• ferro molybdenum is present in an amount in the range of 1 mass% to 5 mass% with respect to the total mass of said melt; and• ferro silicon is present in an amount in the range of 0.5 mass% to 3 mass% with respect to the total mass of said melt.

15. The process as claimed in claim 12, wherein• said melt is present in an amount in the range of 95 mass% to 99 mass% with respect to the total mass of said resultant melt;• yttrium is present in an amount in the range of 0.5 mass% to 1 mass% with respect to the total mass of said resultant melt; and• cerium is present in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of said resultant melt.

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