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A kind of pickling production method of hot-rolled 304 austenitic stainless steel strip

A technology of austenitic stainless steel and production method, which is applied in the pickling production field of hot-rolled 304 austenitic stainless steel strips, can solve the problems of high power consumption, complicated process control, and large pollution of pickling process, and achieve low energy consumption , the effect of simple process

Active Publication Date: 2016-04-20
WISDRI ENG & RES INC LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In view of the above problems, the object of the present invention is to provide a pickling production method for hot-rolled 304 austenitic stainless steel strips, aiming to solve the technical problems of the existing pickling process with large pollution, complicated process control and high power consumption

Method used

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  • A kind of pickling production method of hot-rolled 304 austenitic stainless steel strip

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Effect test

Embodiment 1

[0039] The hot-rolled 304 austenitic stainless steel strip pickling production method that present embodiment provides is as follows:

[0040] A1. Send the strip steel that has been annealed and mechanically broken into the pickling section, and grind and brush the strip steel for the first time. Set the motor speed to 700rpm and the motor current to 250A.

[0041] A2. H 2 SO 4 Pickling, H in the pickling solution 2 SO 4 The concentration is 170g / L, the metal ion concentration is 35g / L, and the temperature is 78°C. Preferably, the pickling time is 35s.

[0042] A3. Grind and pickle the steel strip after sulfuric acid pickling, set the motor speed to 700rpm, and the motor current to 140A.

[0043] A4. Carry out high-current sulfuric acid electrolytic pickling to the strip steel that has been ground and brushed again, and the H in the electrolytic pickling solution 2 SO 4 The concentration is 70g / L, the metal ion concentration is 15g / L, the temperature is 62°C, and the cu...

Embodiment 2

[0046] The hot-rolled 304 austenitic stainless steel strip pickling production method that present embodiment provides is as follows:

[0047] B1. Send the strip steel that has been annealed and mechanically broken into the pickling section, and perform the first grinding and scrubbing on the strip steel. Set the motor speed to 900rpm, and the motor current to 280A.

[0048] B2. H 2 SO 4 Pickling, H in the pickling solution 2 SO 4 The concentration is 190g / L, the metal ion concentration is 45g / L, and the temperature is 82°C. Preferably, the pickling time is 25s.

[0049] B3. Grinding and pickling the steel strip after sulfuric acid pickling, setting the motor speed to 900rpm, and the motor current to 180A.

[0050] B4. Carry out high-current sulfuric acid electrolytic pickling to the strip steel that has been ground and brushed again, and the H in the electrolytic pickling solution 2 SO 4 The concentration is 90g / L, the metal ion concentration is 25g / L, the temperature ...

Embodiment 3

[0053] The hot-rolled 304 austenitic stainless steel strip pickling production method that present embodiment provides is as follows:

[0054] C1. Send the strip steel that has been annealed and mechanically broken into the pickling section, and grind and brush the strip steel for the first time. Set the motor speed between 800rpm and the motor current between 265A.

[0055] C2. H 2 SO 4 Pickling, H in the pickling solution 2 SO 4 The concentration is 180g / L, the metal ion concentration is 40g / L, the temperature is 80°C, and the pickling time is preferably 30s.

[0056] C3. Grind and pickle the steel strip after sulfuric acid pickling, set the motor speed between 800rpm and the motor current between 156A.

[0057] C4. Carry out high-current sulfuric acid electrolytic pickling to the strip steel that has been ground and brushed again, and the H in the electrolytic pickling solution 2 SO 4 The concentration is 80g / L, the metal ion concentration is 20g / L, the temperature is...

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Abstract

The invention is applied to the technical field of stainless steel production, and provides a pickling production method for hot-rolling 304 Austenitic stainless steel strip steel. The method comprises a first grinding brushing step, an H2SO4 pickling step, a second grinding brushing step, a high-current electrolytic pickling step and a low-current electrolytic pickling step. According to the effects of grinding brushing and H2SO4 pickling, most part of oxide skin on the surface of the strip steel is removed, according to the effect of high-current electrolytic pickling, a part of a chromium depletion layer and the residual oxide skin on the surface of the strip steel are removed, and according to the effect of low-current electrolytic pickling, the residual chromium depletion layer is removed, and a layer of passive film is generated on the surface of the strip steel. Compared with the existing technology that pre-pickling of H2SO4 or mixed acid (HNO3+HF) is carried out, and then pickling of the mixed acid is carried out, waste liquid with nitrate and high-pollution nitric oxides are prevented from being generated in the pickling process, and environment pollution can be reduced.

Description

technical field [0001] The invention belongs to the technical field of hot-rolled stainless steel production, and in particular relates to a pickling production method of hot-rolled 304 austenitic stainless steel strip. Background technique [0002] At present, after the hot-rolled 304 austenitic stainless steel strip has been annealed and descaled, sulfuric acid pickling plus mixed acid pickling or mixed acid pickling is generally used. The scale is removed, and then pickled with mixed acid to remove the remaining scale on the surface of the strip and the chromium-poor layer on the surface of the metal substrate, and to form a passivation film on the surface of the strip. However, when pickling with mixed acid, a large amount of waste liquid containing nitrate and highly polluting nitrogen oxides will be produced, which will cause great environmental pollution. [0003] At present, in order to avoid the pollution caused by mixed acid pickling, some foreign factories use H ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C23G3/02C25F3/06
Inventor 李勇华李闽陈海林
Owner WISDRI ENG & RES INC LTD