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Stainless steel plate in the pickling surface blackening should be how to deal with and prevent.

Stainless steel plate in the pickling surface blackening should be how to deal with and prevent.

Time:2022-04-02 Source:Wuxi Jianuo Special Steel Co., Ltd.

Hot-rolled steel strip in the pickling process there is a blackening phenomenon, blackening attached to the hot-rolled raw materials pressed into too deep oxide. The main cause of pickling blackening is the concentration of pickling solution, temperature, rinsing water PH value and hot air dryer temperature is low, etc..

For this reason the corresponding control measures to be taken in the pickling section are.

1、Progress the concentration and temperature of pickling solution Progressing the temperature or concentration of hydrochloric acid can improve the pickling effect, but in the hydrochloric acid solution, the effect of progressing the concentration is better than progressing the temperature, when the acid concentration increases from 2% to 2.5%, the speed of hydrochloric acid pickling progresses 10 times. Therefore, the concentration of hydrochloric acid in pickling tank should be advanced. Through regular dredging of graphite heaters for heating pickling solution, stop changing graphite heaters that cannot meet the heating requirements, and control the temperature of each acid tank according to the request of process regulations to improve the quality of pickling appearance.

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2、Progress the PH value of rinsing water Check the pickling squeezing roller and cylinder before each consumption, stop changing the squeezing roller immediately for the existence of cracks, degumming and serious wear, restore the function of the cylinder of the squeezing roller, and set the cycle of changing the roller according to different positions and different materials of the squeezing roller, stop changing it early before scrapping, progress the squeezing effect of the squeezing roller, reduce the amount of acid brought into the rinsing tank, and progress the PH value of the rinsing water. PH value of rinsing water.

3、Progress the hot air drying temperature and blowing edge effect After the newspaper heating steam pressure ≥ 0.4MPa, the hot air dryer blowing air temperature progresses to more than 120℃, and before the hot air drying installation, equipped with a pair of blowing air blowing edge installation to blow the residual liquid accumulated on both sides of the steel belt to the outside of the steel belt, so that the edge of the steel belt is easy to dry, eliminating the problem of pickled steel belt edge with water.