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Pickling method for surface of austenitic stainless steel before cold bending

An austenitic stainless steel and pickling technology, which is applied in the field of pickling of the front surface of austenitic stainless steel cold-bending, can solve the problems of corrosion and perforation damage of stainless steel, accelerated anode dissolution, and safety hazards of rail transit equipment.

Inactive Publication Date: 2014-05-28
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In particular, when the austenitic stainless steel used for rail transit equipment is cold-formed, a large cathode-small anode structure is formed geometrically, and the anodic dissolution rate of pitting corrosion is accelerated; at the same time, due to the automatic accelerated characteristics, will quickly lead to corrosion perforation failure of stainless steel
This poses a serious hazard to the safety of rail transit equipment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] What the present embodiment is pickled is the 301L stainless steel after the annealing, and its step is as follows:

[0023] (1) Pass the annealed austenitic stainless steel through the No. 1 pickling tank, the medium of the No. 1 pickling tank is 30g / L sodium carbonate solution, add OP-10 emulsifier 4g / L, secondary alkyl sodium sulfonate 3g / L, sodium lauryl sulfate 3g / L, pickling temperature is 80°C, pickling time is 3min;

[0024] (2) Pass the austenitic stainless steel through the No. 2 pickling tank, the medium of the second pickling tank is water, the temperature is 60°C, and the soaking time is 3 minutes;

[0025] (3) Pass the austenitic stainless steel through the No. 1 electrolytic cell, the medium of the No. 1 electrolytic cell is sodium sulfate solution, the solution concentration is 20%, and the current density is 15A / dm 2 , the electrolysis time is 40s;

[0026] (4) Pass the austenitic stainless steel through the No. 2 electrolytic cell, the medium of the ...

Embodiment 2

[0032] What the present embodiment is pickled is the 304 stainless steel after the annealing, and its step is as follows:

[0033] (1) Pass the annealed austenitic stainless steel through the No. 1 pickling tank, the medium of the No. 1 pickling tank is 40g / L sodium carbonate solution, add OP-10 emulsifier 6g / L, secondary alkyl sodium sulfonate 5g / L, sodium lauryl sulfate 4g / L, pickling temperature is 90°C, pickling time is 3min;

[0034] (2) Pass the austenitic stainless steel through the No. 2 pickling tank, the medium of the No. 2 pickling tank is water, the temperature is 70°C, and the soaking time is 2 minutes;

[0035] (3) Pass the austenitic stainless steel through the No. 1 electrolytic cell, the medium of the No. 1 electrolytic cell is sodium sulfate solution, the solution concentration is 25%, and the current density is 20A / dm 2 , the electrolysis time is 60s;

[0036] (4) Pass the austenitic stainless steel through the No. 2 electrolytic cell, the medium of the No. ...

Embodiment 3

[0042] What the present embodiment pickling is the 316 stainless steels after the annealing, and its step is as follows:

[0043] (1) Pass the annealed austenitic stainless steel through the No. 1 pickling tank, the medium of the No. 1 pickling tank is 15g / L sodium carbonate solution, add OP-10 emulsifier 3g / L, secondary alkyl sodium sulfonate 2g / L, sodium lauryl sulfate 2g / L, pickling temperature is 70°C, pickling time is 3min;

[0044] (2) Pass the austenitic stainless steel through the No. 2 pickling tank, the medium of the No. 2 pickling tank is water, the temperature is 50°C, and the soaking time is 2 minutes;

[0045] (3) Pass the austenitic stainless steel through the No. 1 electrolytic cell, the medium of the No. 1 electrolytic cell is sodium sulfate solution, the solution concentration is 10%, and the current density is 12A / dm 2 , the electrolysis time is 30s;

[0046] (4) Pass the austenitic stainless steel through the No. 2 electrolytic cell, the medium of the No....

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Abstract

The invention relates to a pickling method for a surface of austenitic stainless steel before cold bending, and belongs to the technical field of stainless steel surface treatment. The pickling method is characterized in that firstly, an alkaline chemical method is used to remove oil before pickling and a plurality of surfactants are added to improve oil-removing and cleaning effects; during the pickling process, a process combining neutral salts and acid solutions is adopted to reduce pickling cost; hydrochloric acid and sulfuric acid are used to replace a nitric acid solution in a conventional process and additives such as the surfactants and corrosion inhibitors are added to improve the pickling effect; and finally the pickling process combining water washing and neutral salt washing is adopted to remove chloride ions left by previous steps thoroughly. By picking the austenitic stainless steel before cold bending with the method, oxide skins on the surface of the austenitic stainless steel can be removed effectively; metal glossiness of the austenitic stainless steel can be improved; and corrosion resistance of the austenitic stainless steel is improved.

Description

technical field [0001] The invention relates to a pickling method for the cold-bending front surface of austenitic stainless steel, belonging to the technical field of stainless steel surface treatment. Background technique [0002] In recent years, austenitic stainless steel has been widely used in urban rail transit and high-speed railway because of its good appearance and excellent corrosion resistance. At present, austenitic stainless steel profiles for rail transit equipment are mainly manufactured by cold bending forming process. There will be thick oxide skin on the surface of stainless steel before cold bending, which not only affects the appearance quality of stainless steel, but also adversely affects its cold bending performance, such as cold bending cracking and other phenomena. Therefore, the surface scale must be removed by pickling before cold bending. For austenitic, martensitic, ferritic and duplex stainless steels, the pickling process is also dif...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25F1/06
Inventor 姚正军吴小凤魏东博张平则罗西希杨红勤林玉划张泽磊徐尚君
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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