SUS304 stainless steel cold-rolled plate producing method omitting annealing before cold rolling

Abstract

The invention relates to an SUS304 stainless steel cold-rolled plate producing method which omits annealing before cold rolling. The method comprises the steps of smelting, casting, hot rolling, cooling, pickling, cold rolling, solution treatment and pickling, wherein a plate blank is heated to a temperature higher than 1270 DEG C, a hot coil-box is used for temperature preservation before the hot rolling, and the finishing temperature is over 1000 DEG C; cooling is carried out after the rolling, the cooling speed is 25-40 DEG C/s, and coiling is carried out until the coiling temperature reaches 601-650 DEG C; and within 60 minutes after the coiling, a hot rolled coil is positioned in a water tank for cooling, and the hot rolled coil is taken out after the cooling is carried out for 5 or more hours. The method ensures that the SUS304 uniforms crystal grains as much as possible in the process of hot working, avoids corrosion caused by carbide precipitation, realizes the same effect as the adoption of off-line solution treatment, leads to the omission of the off-line solution treatment before the process of cold working and solves the problem that the omission of the off-line solution treatment brings changes to the roll scale structure of the SUS304 hot rolled coil.

Description

technical field [0001] The invention relates to a method for manufacturing a stainless steel cold-rolled plate, in particular to a method for manufacturing a SUS304 stainless steel cold-rolled plate that omits annealing before cold rolling. Background technique [0002] The production process of traditional SUS304 austenitic stainless steel cold-rolled plate is as follows: [0003] Hot working process→offline solid solution→pickling→cold working process→offline solid solution→pickling. [0004] Due to the high carbon content of SUS304 austenitic stainless steel (≥0.03%), it must be subjected to off-line solution treatment after the thermal processing of SUS304. The purpose of this treatment is mainly two: 1. Re-solution in Chromium-iron carbides (mainly M 23 C 6 ) to prevent corrosion problems during use or pickling; 2. Homogenize austenite grains to improve the cold workability of SUS304. Nowadays, some research institutions at home and abroad have begun to improve equi...

AI Technical Summary

Problems solved by technology

[0010] Some patents require higher final rolling temperature, but do not provide a method to ensure the final rolling temperature, and to ensure that the hot-rolled stainless steel strip is coiled at the specified coiling temperature, the capacity of the equipment may not be enough of;

[0011] In some patents, although the coiling temperature is low, the final rolling temperature is also low and the cooling rate is slow. In this case, the carbide precipitation cannot be completely avoided, and the lower final rolling temperature will also cause heat The strength of rolled austenitic stainless steel is greatly increased, and the grain uniformity is poor;

[0012] Some patents also mention that the thermal processing optimization process adopted can omit the off-line solution treatment process before the cold processing process, but none of them involve whether the change of the thermal processing process parameters will affect the cold processing process, and there is no mention of the thermal processing process. Changes in parameters will make how to adjust the cold working process

[0013] In addition, according to the actual situation, even if the coiling temperature of the hot-rolled coil is very low, the hot-rolled coil will take a long time to cool down to room temperature. measures, it is difficult to avoid the precipitation of carbides

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