Joint production method for stainless steel coils with different surface grades

Abstract

The invention relates to a joint production method for stainless steel coils with different surface grades, which comprises the following steps of: feeding a stainless steel 400 series black skin coil to an uncoiler for uncoiling, welding the head part of the uncoiled strip steel to the tail part of the previous coil of strip steel through a welding machine, polishing a welding seam, and feeding into an inlet loop; the strip steel conveyed and output through the inlet loop is conveyed into a continuous mill to be rolled, and then the strip steel is conveyed into a middle loop after being cleaned; or the strip steel is fed into a transition platform arranged below the continuous mill, and the strip steel output after passing through the transition platform enters the middle loop; feeding the strip steel output by the middle loop into an annealing furnace, and then dephosphorizing and polishing to obtain glossy strip steel; and the glossy strip steel is fed into an acid pickling section to be subjected to acid pickling, flattening and other operations, and then a finished product is obtained. The method not only can be used for producing stainless steel products with 2E surfaces or near 2B surfaces, but also can be used for producing stainless steel products with NO.1 surfaces, and has excellent application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of stainless steel production, in particular to a method for jointly producing stainless steel coils with different surface grades. Background Art

[0002] The surface grade of stainless steel is mainly classified according to its treatment method, finish, brightness and applicable scenarios. The common grades are as follows:

[0003] 1D: The surface has a pure iron finish and is often used to manufacture stainless steel plates that require sheet metal processing.

[0004] 2D: The surface finish is relatively poor, but after rolling, it can be subjected to the next step of cold rolling.

[0005] NO.1 (hot-rolled surface): The surface is hot-rolled and presents a metallic luster, but there may be defects such as indentations and oxide scale. It is generally used for industrial processing, such as cold-rolled materials, industrial tanks, and chemical industrial equipment.

[0006] 2B (matte): After cold rolling, heat treatment, pickling, and then fine rolling, the surface is moderately bright. This surface is relatively smooth and easy to re-grind. It is widely used, such as tableware, building materials, etc. Although there may be slight scratches and uneven polishing during use, it will not affect its overall use effect.

[0007] 2E surface: with oxide scale, cold rolled, heat treated, descaling; the surface state is rough and matte; this surface type is cold rolled with oxide scale, and the descaling method is pickling or mechanical descaling plus pickling. It is suitable for structural parts or cold-rolled alternative products with high thickness accuracy and high surface roughness requirements.

[0008] BA (bright surface): The surface is obtained by cold rolling, bright annealing and flattening. This surface has excellent gloss and high reflectivity, just like a mirror, and is suitable for applications that require high brightness and finish, such as high-end furniture, electrical appliances, kitchen utensils and pharmaceutical equipment.

[0009] At present, stainless steel with different surface grades is usually processed by a fixed set of processes. The processing equipment is relatively fixed, and it is impossible to produce steel coils with different surface grades on a set of equipment, which limits the production capacity of manufacturers. At the same time, it is difficult to lay out multiple production lines in a limited space. Therefore, adding production lines means increasing the factory floor space, which will increase the factory's investment and production costs. Summary of the invention

[0010] The purpose of the present invention is to overcome the problems of large floor space and high production cost in the existing production of stainless steel with different surface grades, and to provide a joint production method for stainless steel coils with different surface grades. The method can realize the joint production of stainless steel with 2E surface, nearly 2B surface and NO.1 surface without adding production lines, saving space and production costs.

[0011] The near 2B surface in the present invention means that the surface requirements of the stainless steel are lower than the existing 2B surface requirements, and higher than the 2E surface requirements.

[0012] The specific plan is as follows:

[0013] A method for the joint production of stainless steel coils with different surface grades comprises the following steps:

[0014] (1) The stainless steel 400 series black coil is sent to the uncoiler for uncoiling. The head of the uncoiled strip is welded to the tail of the previous strip by a welding machine. The weld is polished and smoothed and then sent to the inlet looper;

[0015] (2) sending the steel strip outputted through the inlet looper into a continuous rolling mill for rolling, and then cleaning it and sending it into an intermediate looper; or sending it into a transition platform arranged below the continuous rolling mill, and the steel strip outputted through the transition platform enters the intermediate looper;

[0016] (3) sending the steel strip outputted from the intermediate looper into an annealing furnace, and then dephosphorizing and polishing the steel strip to obtain a glossy steel strip;

[0017] (4) feeding the glossy steel strip into a pickling section for pickling, wherein the pickling comprises first electrolyzing the steel strip with a neutral salt, then electrolyzing the steel strip in a nitric acid solution, and finally washing the steel strip in a mixed acid solution; or the pickling comprises sequentially washing the steel strip with sulfuric acid and a mixed acid solution to obtain a steel strip with a clean surface;

[0018] (5) The cleaned strip is fed into a flattening machine to improve the shape and surface roughness, and then the end is sheared and rolled to obtain a finished product.

[0019] Furthermore, the stainless steel 400 series black coil is straightened and dephosphorized in advance, and after the treatment, a part of the iron oxide scale on the surface is removed by high-pressure water cleaning.

[0020] Furthermore, the continuous rolling mill is an 18-roller rolling mill or a 6-roller rolling mill, and the reduction rate is 75-85%.

[0021] Furthermore, the annealing TV value of the annealing furnace is less than or equal to 240 mm×m / min.

[0022] Furthermore, the temperature of the annealing furnace is 880-950°C.

[0023] Furthermore, the speed at which the steel strip enters the annealing furnace is 100-300 m / min.

[0024] Furthermore, the transition platform is provided with rollers for supporting the strip steel, and deviation-correcting rollers are respectively installed at both ends of the axial direction of the rollers for adjusting the running direction of the strip steel.

[0025] Furthermore, the mixed acid solution is a mixture of hydrofluoric acid and nitric acid.

[0026] Further, the steps for producing a stainless steel coil with a 2E surface or a near 2B surface include:

[0027] (1) The stainless steel 400 series black coil is sent to the uncoiler for uncoiling. The head of the uncoiled strip is welded to the tail of the previous strip by a welding machine. The weld is polished and smoothed and then sent to the inlet looper;

[0028] (2) feeding the strip steel outputted through the inlet looper into a continuous rolling mill for rolling, and then cleaning it and feeding it into an intermediate looper;

[0029] (3) sending the steel strip outputted from the intermediate looper into an annealing furnace, and then dephosphorizing and polishing the steel strip to obtain a glossy steel strip;

[0030] (4) sending the glossy steel strip to a pickling section for pickling, wherein the steel strip is first electrolyzed in a neutral salt, then electrolyzed in a nitric acid solution, and finally washed in a mixed acid solution to obtain a steel strip with a clean surface;

[0031] (5) The cleaned strip is fed into a flattening machine to improve the shape and surface roughness, and then the end is sheared and rolled to obtain a finished product.

[0032] Further, the steps for producing the NO.1 surface stainless steel coil include:

[0033] (1) The stainless steel 400 series black coil is sent to the uncoiler for uncoiling. The head of the uncoiled strip is welded to the tail of the previous strip by a welding machine. The weld is polished and smoothed and then sent to the inlet looper;

[0034] (2) sending the steel strip outputted through the inlet looper to the transition platform, and the steel strip outputted after passing through the transition platform enters the intermediate looper;

[0035] (3) sending the steel strip outputted from the intermediate looper into an annealing furnace, and then dephosphorizing and polishing the steel strip to obtain a glossy steel strip;

[0036] (4) sending the glossy steel strip to a pickling section for pickling, wherein the pickling is to sequentially wash the steel strip with sulfuric acid and a mixed acid solution to obtain a steel strip with a clean surface;

[0037] (5) The cleaned strip is fed into a flattening machine to improve the shape and surface roughness, and then the end is sheared and rolled to obtain a finished product.

[0038] Beneficial effects: The combined production method of stainless steel coils with different surface grades provided by the present invention can be used to produce stainless steel coils with 2E surface or nearly 2B surface, and can also be used to produce stainless steel coils with NO.1 surface, expanding different product types on one production line, saving workshop area and production costs, and having industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings will be briefly introduced below. Obviously, the accompanying drawings in the following description only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0040] Figure 1 It is a schematic diagram of the device structure provided by an embodiment 1 of the present invention. The meanings of the numbers in the figure are: NO.1 uncoiler 1, NO.2 uncoiler 2, welding machine 3, inlet looper 4, continuous rolling mill 5, cleaning mechanism 6, intermediate looper 7, annealing furnace 8, phosphorus breaking machine 9, shot blasting machine 10, pickling mechanism 11, outlet looper 12, leveling machine 13, outlet slitting and shearing mechanism 14, NO.1 coiler 15, NO.2 coiler 16, transition platform 17. DETAILED DESCRIPTION

[0041] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. In the examples, those without specifying specific techniques or conditions are carried out according to the techniques or conditions described in the literature in this area or according to the product specification. Those without specifying the manufacturer of reagents or instruments used are all conventional products that can be obtained commercially. In the following examples, if not clearly stated, "%" refers to weight percentage.

[0042] Example 1

[0043] A method for the combined production of stainless steel coils of different surface grades, using Figure 1The equipment shown includes a NO.1 uncoiler 1, a NO.2 uncoiler 2, a welding machine 3, an inlet looper 4, a continuous rolling mill 5, a cleaning mechanism 6, an intermediate looper 7, an annealing furnace 8, a phosphorus breaking machine 9, a shot blasting machine 10, a pickling mechanism 11, an outlet looper 12, a leveling machine 13, an outlet slitting and shearing mechanism 14, a NO.1 coiler 15, a NO.2 coiler 16 and a transition platform 17. Specifically, the NO.1 uncoiler 1 and the NO.2 uncoiler 2 are connected to the welding machine 3 respectively, the outlet of the welding machine 3 is connected to the inlet of the inlet looper 4, and the outlet of the inlet looper 4 is connected to the outlet of the inlet looper 4. The outlets of the continuous rolling mill 5 are respectively connected to the inlet of the cleaning mechanism 6, the outlet of the cleaning mechanism 6 is connected to the inlet of the intermediate looper 7, the outlet of the intermediate looper 7 and the outlet of the transition platform 17 are respectively connected to the inlet of the annealing furnace 8; the outlet of the annealing furnace 8 is sequentially connected to the phosphorus breaking machine 9, the shot blasting machine 10, the pickling mechanism 11, the outlet looper 12, the leveling machine 13 and the outlet slitting and shearing mechanism 14, and the outlets of the outlet slitting and shearing mechanism 14 are respectively connected to the NO.1 coiler 15 and the NO.2 coiler 16.

[0044] The specific method includes the following steps:

[0045] (1) The stainless steel 400 series black coil is sent to the unwinding machine for unwinding. The head of the unwinding strip is welded to the tail of the previous strip by a welding machine. The weld is polished and smoothed before being sent to the entrance looper. Since it is difficult to remove the iron oxide scale on the surface of the stainless steel 400 series black coil, it is straightened and dephosphorized before unwinding. After the treatment, high-pressure water is used to remove part of the surface iron oxide scale before entering the entrance looper.

[0046] (2) The strip steel outputted through the said inlet loop is sent to the continuous rolling mill for rolling, and then sent to the intermediate loop after cleaning; or sent to the transition platform arranged below the said continuous rolling mill, and the strip steel outputted after passing through the said transition platform enters the said intermediate loop. Among them, the continuous rolling mill adopts an 18-roller rolling mill or a 6-roller rolling mill, which is designed as 3 to 5 frames, and the reduction rate reaches 80% to meet the thickness requirements of the strip steel thinning. In order to ensure the surface quality, rolling oil is used for rolling, so the residual oil on the surface needs to be removed by cleaning after rolling. If thinning is not required, it is not necessary to pass through the continuous rolling mill, but enter the transition platform, which is provided with rollers for supporting the strip steel, and deviation correction rollers are respectively installed at both ends along the axial direction of the rollers to adjust the running direction of the strip steel.

[0047] (3) The strip steel outputted from the intermediate looper is sent to an annealing furnace, and then dephosphorized and polished to obtain a shiny strip steel. The maximum annealing TV value is 240 mm·m / min, and the strip steel speed is 200 m / min.

[0048] (4) The glossy steel strip is sent to a pickling section for pickling. The pickling comprises first electrolyzing the steel strip with a neutral salt, then electrolyzing it in a nitric acid solution, and finally electrolyzing it in a mixed acid solution (HF+HNO 3 ) in the strip; or the pickling is carried out by sequentially washing the strip with sulfuric acid and a mixed acid solution (HF+HNO 3 ) to obtain a strip with a clean surface. The pickling section uses two different pickling paths in parallel to achieve different levels of quality requirements for the stainless steel surface.

[0049] (5) The cleaned strip is fed into a flattening machine to improve the shape and surface roughness, and then the end is sheared and rolled to obtain a finished product.

[0050] Example 2

[0051] Based on Example 1, this example further introduces a method for producing a stainless steel 2E surface product or a nearly 2B surface product, comprising the following steps:

[0052] (1) The stainless steel 400 series black coil is sent to the uncoiler for uncoiling. The head of the uncoiled strip is welded to the tail of the previous strip by a welding machine. The weld is polished and smoothed and then sent to the inlet looper;

[0053] (2) feeding the strip steel outputted through the inlet looper into a continuous rolling mill for rolling, with a reduction rate of 75-85%, and then washing it and feeding it into an intermediate looper;

[0054] (3) sending the steel strip outputted from the intermediate looper into an annealing furnace, the temperature of the annealing furnace is 950° C., the annealing TV value is 220 mm·m / min, and then dephosphorizing and polishing are performed to obtain a steel strip with gloss;

[0055] (4) sending the glossy steel strip to a pickling section for pickling, wherein the steel strip is first electrolyzed in a neutral salt, then electrolyzed in a nitric acid solution, and finally washed in a mixed acid solution to obtain a steel strip with a clean surface;

[0056] (5) The cleaned strip is fed into a flattening machine to improve the shape and surface roughness, and then the end is sheared and rolled to obtain a finished product.

[0057] Example 3

[0058] Based on Example 1, this example further introduces a method for producing a stainless steel NO.1 surface product, comprising the following steps:

[0059] (1) The stainless steel 400 series black coil is sent to the uncoiler for uncoiling. The head of the uncoiled strip is welded to the tail of the previous strip by a welding machine. The weld is polished and smoothed and then sent to the inlet looper;

[0060] (2) sending the steel strip outputted through the inlet looper to the transition platform, and the steel strip outputted after passing through the transition platform enters the intermediate looper;

[0061] (3) sending the steel strip outputted from the intermediate looper into an annealing furnace, the temperature of the annealing furnace is 880° C., the annealing TV value is 200 mm·m / min, and then dephosphorizing and polishing are performed to obtain a steel strip with gloss;

[0062] (4) sending the glossy steel strip to a pickling section for pickling, wherein the pickling is to sequentially wash the steel strip with sulfuric acid and a mixed acid solution to obtain a steel strip with a clean surface;

[0063] (5) The cleaned strip is fed into a flattening machine to improve the shape and surface roughness, and then the end is sheared and rolled to obtain a finished product.

[0064] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0065] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0066] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for the joint production of stainless steel coils with different surface grades, characterized in that: The following steps are involved: (1) The stainless steel 400 series black coil is sent to the uncoiler for uncoiling. The head of the uncoiled strip is welded to the tail of the previous strip by a welding machine. The weld is polished and smoothed and then sent to the inlet looper; (2) sending the steel strip outputted through the inlet looper into a continuous rolling mill for rolling, and then cleaning it and sending it into an intermediate looper; or sending it into a transition platform arranged below the continuous rolling mill, and the steel strip outputted through the transition platform enters the intermediate looper; (3) sending the steel strip outputted from the intermediate looper into an annealing furnace, and then dephosphorizing and polishing the steel strip to obtain a glossy steel strip; (4) feeding the glossy steel strip into a pickling section for pickling, wherein the pickling comprises first electrolyzing the steel strip with a neutral salt, then electrolyzing the steel strip in a nitric acid solution, and finally washing the steel strip in a mixed acid solution; or the pickling comprises sequentially washing the steel strip with sulfuric acid and a mixed acid solution to obtain a steel strip with a clean surface; (5) The cleaned strip is fed into a flattening machine to improve the shape and surface roughness, and then the end is sheared and rolled to obtain a finished product.

2. The method for jointly producing stainless steel coils with different surface grades according to claim 1, characterized in that: The stainless steel 400 series black coil is straightened and dephosphorized in advance, and then washed with high-pressure water to remove part of the iron oxide on the surface.

3. The method for jointly producing stainless steel coils with different surface grades according to claim 2, characterized in that: The continuous rolling mill is an 18-roller rolling mill or a 6-roller rolling mill, and the reduction rate is 75-85%.

4. The method for jointly producing stainless steel coils with different surface grades according to claim 1, characterized in that: The annealing TV value of the annealing furnace is less than or equal to 240 mm·m / min.

5. The method for jointly producing stainless steel coils with different surface grades according to claim 4, characterized in that: The temperature of the annealing furnace is 880-950°C.

6. The method for jointly producing stainless steel coils with different surface grades according to claim 5, characterized in that: The speed at which the steel strip enters the annealing furnace is 100-300 m / min.

7. The method for jointly producing stainless steel coils with different surface grades according to any one of claims 1 to 6, characterized in that: The transition platform is provided with rollers for supporting the strip steel, and deviation-correcting rollers are respectively installed at both ends of the axial direction of the rollers for adjusting the running direction of the strip steel.

8. The method for jointly producing stainless steel coils with different surface grades according to any one of claims 1 to 6, characterized in that: The mixed acid solution is a mixture of hydrofluoric acid and nitric acid.

9. The method for jointly producing stainless steel coils with different surface grades according to any one of claims 1 to 6, characterized in that: The steps for producing 2E surface or nearly 2B surface stainless steel coils include: (1) The stainless steel 400 series black coil is sent to the uncoiler for uncoiling. The head of the uncoiled strip is welded to the tail of the previous strip by a welding machine. The weld is polished and smoothed and then sent to the inlet looper; (2) feeding the strip steel outputted through the inlet looper into a continuous rolling mill for rolling, and then cleaning it and feeding it into an intermediate looper; (3) sending the steel strip outputted from the intermediate looper into an annealing furnace, and then dephosphorizing and polishing the steel strip to obtain a glossy steel strip; (4) sending the glossy steel strip to a pickling section for pickling, wherein the steel strip is first electrolyzed in a neutral salt, then electrolyzed in a nitric acid solution, and finally washed in a mixed acid solution to obtain a steel strip with a clean surface; (5) The cleaned strip is fed into a flattening machine to improve the shape and surface roughness, and then the end is sheared and rolled to obtain a finished product.

10. The method for jointly producing stainless steel coils with different surface grades according to any one of claims 1 to 6, characterized in that: The steps for producing NO.1 surface stainless steel coil include: (1) The stainless steel 400 series black coil is sent to the uncoiler for uncoiling. The head of the uncoiled strip is welded to the tail of the previous strip by a welding machine. The weld is polished and smoothed and then sent to the inlet looper; (2) sending the steel strip outputted through the inlet looper to the transition platform, and the steel strip outputted after passing through the transition platform enters the intermediate looper; (3) sending the steel strip outputted from the intermediate looper into an annealing furnace, and then dephosphorizing and polishing the steel strip to obtain a glossy steel strip; (4) sending the glossy steel strip to a pickling section for pickling, wherein the pickling is to sequentially wash the steel strip with sulfuric acid and a mixed acid solution to obtain a steel strip with a clean surface; (5) The cleaned strip is fed into a flattening machine to improve the shape and surface roughness, and then the end is sheared and rolled to obtain a finished product.

Images