A cold-rolled nickel-reduced austenitic stainless steel and a method for manufacturing the same

Abstract

The present application relates to a kind of cold-rolled nickel austenitic stainless steel and its manufacturing method, and the chemical composition of steel plate is as follows: C 0.070%~0.120%, Si 0.30%~0.70%, Mn 10.00%~10.60%, Ni 0.60%~1.20%, Cr 13.00%~14.00%, Cu 0.50%~1.20%, N 0.150%~0.180%, and the rest is Fe and inevitable impurities.The present application adopts multi-pass reciprocating rolling process, and reduces pass rolling reduction;When cold-rolled annealing pickling, adjust annealing curve, reduce production speed, and improve furnace temperature;The 2B product produced can be used for 8K mirror surface plate, and the product yield and added value are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of stainless steel production, in particular to a cold-rolled nickel-saving austenitic stainless steel and a manufacturing method thereof. BACKGROUND

[0002] Nickel-saving austenitic stainless steel is an economical stainless steel product with single austenitic structure at room temperature, which is formed by increasing manganese and nitrogen elements on the basis of traditional austenitic stainless steel 304 to save the cost and reduce the addition amount of noble metal nickel. Nickel-saving austenitic stainless steel has excellent mechanical properties, certain corrosion resistance, good heat resistance and low temperature strength, and therefore has been increasingly concerned in recent years, and new varieties are continuously developed. However, nickel-saving stainless steel is prone to cracking during forming, which directly affects the application of nickel-saving austenitic stainless steel.

[0003] The nickel-saving austenitic stainless steel produced by the conventional process has high hardness, and the thinner the thickness of the 2B (a code for the surface quality of stainless steel plate) product is, the higher the hardness is. High hardness increases the risk of cracking during downstream forming processing, affecting the yield rate.

[0004] It is found by comparing different cold rolling processes that the hardness of the 2B product by reciprocating rolling is lower than that by continuous rolling, and increasing the cold rolling annealing temperature and reducing the furnace zone speed can also reduce the hardness. SUMMARY

[0005] The present application provides a kind of cold-rolled nickel-saving austenitic stainless steel and its manufacturing method, adopt multi-pass reciprocating rolling process, and reduce pass rolling reduction;When cold rolling annealing and pickling, adjust annealing curve, reduce production speed, and increase furnace zone temperature;The 2B product produced can be used for 8K mirror surface plate, which improves the product yield rate and added value.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0007] A low-hardness cold-rolled nickel-saving austenitic stainless steel, the chemical composition of the steel plate is as follows in terms of mass percentage: C 0.070% to 0.120%, Si 0.30% to 0.70%, Mn 10.00% to 10.60%, Ni 0.60% to 1.20%, Cr 13.00% to 14.00%, Cu 0.50% to 1.20%, N 0.150% to 0.180%, and the rest is Fe and unavoidable impurities.

[0008] Further, the thickness of the steel plate is less than or equal to 0.9 mm.

[0009] A manufacturing method of a low-hardness cold-rolled nickel-saving austenitic stainless steel, the production process is controlled as follows:

[0010] 1) 2B steel plate adopts reciprocating rolling when cold rolling, the rolling pass is proportional to the total rolling reduction, and the pass reduction gradually decreases with the number of cold rolling passes;

[0011] 2) annealing after cold rolling, the steel plate discharge temperature is controlled above 950℃, and the steel plate running speed in the furnace zone is <140 mpm.

[0012] Further, the relationship between the rolling pass, the total rolling reduction and the pass reduction is as follows:

[0013] When the rolling pass is three passes, the total rolling reduction is not less than 42%, the first pass reduction is not less than 21%, and the second and third pass reductions gradually decrease;

[0014] When the rolling pass is four passes, the total rolling reduction is not less than 44%, the first pass reduction is not less than 22%, and the second to fourth pass reductions gradually decrease;

[0015] When the rolling pass is five passes, the total rolling reduction is not less than 51%, the first pass reduction is not less than 20%, and the second to fifth pass reductions gradually decrease;

[0016] When the rolling pass is six passes, the total rolling reduction is not less than 55%, the first pass reduction is not less than 21%, and the second to sixth pass reductions gradually decrease;

[0017] When the rolling pass is seven passes, the total rolling reduction is not less than 52%, the first pass reduction is not less than 15%, and the second to seventh pass reductions gradually decrease.

[0018] Further, during the annealing, the relationship between the steel plate temperature and the steel plate running speed and the steel plate thickness is as follows:

[0019] When the steel plate thickness is ≤0.60 mm, the steel plate temperature is 900-1000℃, and the steel plate running speed is 100-140 mpm;

[0020] When 0.60 mm < steel plate thickness ≤0.70 mm, the steel plate temperature is 910-1010℃, and the steel plate running speed is 95-135 mpm;

[0021] When 0.70 mm < steel plate thickness ≤0.80 mm, the steel plate temperature is 920-1020℃, and the steel plate running speed is 90-130 mpm;

[0022] When 0.80 mm < steel plate thickness ≤0.90 mm, the steel plate temperature is 930-1030℃, and the steel plate running speed is 85-125 mpm.

[0023] Further, the annealing adopts continuous annealing, and the temperatures in 1# furnace to 9# furnace are controlled as follows:

[0024] 1# furnace temperature: 850~900℃; 2# furnace temperature: 880~980℃; 3# furnace temperature: 930~1030℃; 4# furnace temperature: 940~1040℃; 5# furnace temperature: 950~1050℃; 6# furnace temperature: 930~1030℃; 7# furnace temperature: 950~1050℃; 8# furnace temperature: 960~1060℃; 9# furnace temperature: 950~1050℃.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] The multi-pass reciprocating rolling process is adopted, and the pass rolling reduction is reduced; the annealing curve is adjusted during cold rolling, annealing and pickling, the production speed is reduced, and the furnace temperature is increased; the produced 2B product can be used for 8K mirror surface plate (also called 8K plate or mirror surface plate, that is, the plate surface is polished by a polishing device through polishing liquid, so that the plate surface brightness is as clear as a mirror; at present, it is widely used in luxurious decoration of star-rated hotels, large-scale shopping malls and the like, and can also be used as decoration of elevator car plate, carriage plate and the like), and the product yield and added value are improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a typical metallographic structure photo of the cold-rolled nickel-saving austenitic stainless steel according to the present application. DETAILED DESCRIPTION

[0028] The low-hardness cold-rolled nickel-saving austenitic stainless steel according to the present application has the following chemical composition of the steel plate in terms of mass percentage: C 0.070%~0.120%, Si 0.30%~0.70%, Mn 10.00%~10.60%, Ni 0.60%~1.20%, Cr 13.00%~14.00%, Cu 0.50%~1.20%, N 0.150%~0.180%, and the rest is Fe and inevitable impurities. The typical metallographic structure photo of the cold-rolled nickel-saving austenitic stainless steel is shown in Figure 1 .

[0029] Further, the thickness of the steel plate is less than or equal to 0.9mm.

[0030] The manufacturing method of the low-hardness cold-rolled nickel-saving austenitic stainless steel according to the present application controls the following production process:

[0031] 1) The 2B steel plate is cold-rolled by using reciprocating rolling, the rolling pass is proportional to the total rolling reduction, and the pass rolling reduction is gradually reduced with the number of cold rolling passes;

[0032] 2) After cold rolling, the annealing temperature of the steel plate is controlled to be higher than or equal to 950℃, and the running speed of the steel plate in the furnace area is less than 140mpm.

[0033] Further, the relationship between the rolling pass, the total cold rolling reduction and the pass reduction is as follows:

[0034] When the rolling pass is three passes, the total reduction is not less than 42%, the first pass reduction is not less than 21%, and the second and third pass reductions gradually decrease;

[0035] When the rolling pass is four passes, the total reduction is not less than 44%, the first pass reduction is not less than 22%, and the second to fourth pass reductions gradually decrease;

[0036] When the rolling pass is five passes, the total reduction is not less than 51%, the first pass reduction is not less than 20%, and the second to fifth pass reductions gradually decrease;

[0037] When the rolling pass is six passes, the total reduction is not less than 55%, the first pass reduction is not less than 21%, and the second to sixth pass reductions gradually decrease.

[0038] When the rolling pass is seven passes, the total reduction is not less than 52%, the first pass reduction is not less than 15%, and the second to seventh pass reductions gradually decrease.

[0039] Further, during the annealing, the relationship between the steel plate temperature and the steel plate running speed and the steel plate thickness is as follows:

[0040] When the steel plate thickness is less than or equal to 0.60 mm, the steel plate temperature is 900-1000℃, and the steel plate running speed is 100-140 mpm;

[0041] When the steel plate thickness is greater than 0.60 mm and less than or equal to 0.70 mm, the steel plate temperature is 910-1010℃, and the steel plate running speed is 95-135 mpm;

[0042] When the steel plate thickness is greater than 0.70 mm and less than or equal to 0.80 mm, the steel plate temperature is 920-1020℃, and the steel plate running speed is 90-130 mpm;

[0043] When the steel plate thickness is greater than 0.80 mm and less than or equal to 0.90 mm, the steel plate temperature is 930-1030℃, and the steel plate running speed is 85-125 mpm.

[0044] Further, the annealing is continuous annealing, and the temperatures in the 1# furnace to the 9# furnace are controlled as follows:

[0045] 1# furnace furnace temperature: 850~900℃; 2# furnace furnace temperature: 880~980℃; 3# furnace furnace temperature: 930~1030℃; 4# furnace furnace temperature: 940~1040℃; 5# furnace furnace temperature: 950~1050℃; 6# furnace furnace temperature: 930~1030℃; 7# furnace furnace temperature: 950~1050℃; 8# furnace furnace temperature: 960~1060℃; 9# furnace furnace temperature: 950~1050℃.

[0046] The following examples are carried out on the basis of the technical solutions of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following examples. The methods used in the following examples are all conventional methods unless otherwise specified.

[0047]

Example

[0048] In this embodiment, the main chemical components (except Fe, mass percentage) of a low-hardness cold-rolled nickel-reduced austenitic stainless steel are shown in Table 1, the cold-rolling process parameters are shown in Table 2, and the annealing process parameters are shown in Table 3.

[0049] Table 1

[0050]

[0051] Table 2

[0052]

[0053] Table 3

[0054]

[0055] The above description is only the preferred specific implementation mode of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art, according to the technical solutions and the inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A method of manufacturing a low-hardness cold-rolled nickel-saving austenitic stainless steel, characterized by, The steel plate has the following chemical components in percentage by mass: C 0.070%-0.120%, Si 0.30%-0.34%, Mn 10.00%-10.60%, Ni 0.60%-0.94%, Cr 13.00%-13.98%, Cu 0.50%-0.53%, N 0.150%-0.180%, and the rest is Fe and inevitable impurities; the thickness of the steel plate is 0.5-0.9 mm; The manufacturing method of the low-hardness cold-rolled nickel-reduced austenitic stainless steel controls the following production process: 1) Reciprocating rolling is adopted when the 2B steel plate is cold-rolled, the rolling pass is proportional to the total rolling reduction, and the pass reduction is gradually reduced with the number of cold rolling passes; 2) Annealing after cold rolling, continuous annealing is adopted, and the temperature in the 1#-9# furnace is controlled as follows: the temperature in the 1# furnace is 850-900 ℃; the temperature in the 2# furnace is 880-980 ℃; the temperature in the 3# furnace is 930-1030 ℃; the temperature in the 4# furnace is 940-1040 ℃; the temperature in the 5# furnace is 950-1050 ℃; the temperature in the 6# furnace is 930-1030 ℃; the temperature in the 7# furnace is 950-1050 ℃; the temperature in the 8# furnace is 960-1060 ℃; and the temperature in the 9# furnace is 950-1050 ℃; The steel plate is discharged at a temperature of 950 ℃ or above, and the running speed of the steel plate in the furnace area is less than 140 mpm; during annealing, the relationship between the temperature of the steel plate and the running speed of the steel plate and the thickness of the steel plate is as follows: When the thickness of the steel plate is less than or equal to 0.60 mm, the temperature of the steel plate is 900-1000 ℃, and the running speed of the steel plate is 100-140 mpm; When the thickness of the steel plate is greater than 0.60 mm and less than or equal to 0.70 mm, the temperature of the steel plate is 910-1010 ℃, and the running speed of the steel plate is 95-135 mpm; When the thickness of the steel plate is greater than 0.70 mm and less than or equal to 0.80 mm, the temperature of the steel plate is 920-1020 ℃, and the running speed of the steel plate is 90-130 mpm; When the thickness of the steel plate is greater than 0.80 mm and less than or equal to 0.90 mm, the temperature of the steel plate is 930-1030 ℃, and the running speed of the steel plate is 85-125 mpm.

2. The method of producing a low-hardness cold-rolled nickel-saving austenitic stainless steel according to claim 1, characterized by, The relationship between the rolling pass, the total rolling reduction, and the pass reduction is as follows: When the rolling pass is three passes, the total rolling reduction is not less than 42%, the first pass reduction is not less than 21%, and the second pass reduction and the third pass reduction are gradually reduced; When the rolling pass is four passes, the total rolling reduction is not less than 44%, the first pass reduction is not less than 22%, and the second pass reduction to the fourth pass reduction are gradually reduced; When the rolling pass is five passes, the total rolling reduction is not less than 51%, the first pass reduction is not less than 20%, and the second pass reduction to the fifth pass reduction are gradually reduced; When the rolling pass is six passes, the total rolling reduction is not less than 55%, the first pass reduction is not less than 21%, and the second pass reduction to the sixth pass reduction are gradually reduced; When the rolling pass is seven passes, the total rolling reduction is not less than 52%, the first pass reduction is not less than 15%, and the second pass reduction to the seventh pass reduction are gradually reduced.

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