不锈钢中厚板在线酸洗工艺研究进展

New technology and advance of pickling process of stainless steel plate

在原卧式连续喷淋酸洗机组,应用H_2SO_4+(HNO_3+HF)酸洗液技术、一段式混酸(HNO_3+HF)酸洗液技术酸洗不锈钢中厚板304系列产品,出现表面色差、上表面辊印缺陷。针对这些缺陷,以304系列不锈钢中厚板为代表,论述两段式混酸(HNO_3+HF)液酸洗方法,开展两段式混酸(HNO_3+HF)液酸洗方法的工艺试验和研究,并对原卧式喷淋酸洗生产线进行技术改造。采用两段式混酸(HNO_3+HF)液工艺技术,酸洗304系列不锈钢中厚板。在预先酸洗工艺段,混酸液HNO_3为220 g/L、HF为45 g/L,混酸液温度为46℃;在最终酸洗工艺段,混酸液HNO_3为280 g/L、HF为20 g/L,混酸液温度为41℃。酸洗后的钢板表面银白色,一次抛丸酸洗合格率90%以上。

The oxide scale of 304 stainless steel plate is to remove by pickling process. Surface pickling defects,such as color difference of plate surface and roll marks defects,are easy to be generated with horizontal continuous spray pickling process which cause lower efficiency. A new twostep mixed acid（ HNO3＋ HF） pickling process is introduced,the main process parameters are HNO3 220 g/L ＋ HF 45 g/L in pre-pickling process,HNO3 280 g/L ＋ HF 20 g/L in final pickling process,the pickling temperature are 46 ℃ in pre-pickling process,41 ℃ in final pickling process.With this two-step mixed acid pickling process,the surface quality becomes much better,the color difference of plate surface and roll marks defects almost disappeared,the efficiency of the pickling line is improved greatly,and the once qualified rate is over 90%.