无模拉拔不锈钢锥形管高温氧化及氧化膜化学去除工艺

High temperature oxidation and oxide-film chemical removal technology of stainless steel cone-shape pipe in dieless drawing

以304不锈钢锥形管为例,分析了无模拉拔锥形管表面氧化膜影响因素及厚度分布规律,研究了酸洗温度、酸洗速度等工艺参数对化学去除氧化膜过程的影响。结果表明,无模拉拔304不锈钢锥形管表面氧化膜厚度随着变形程度、锥形管的长度、感应加热温度、冷热源距离的增大而增大,并且随进料速度的减小而增大;在组成为98%H2SO4(80～100 mL.L-1)、NaNO3(40～50 g.L-1)、NaCl(10～20 g.L-1)、乌洛托品(3～5 g.L-1)的酸洗溶液中,酸洗温度70～80℃的条件下,为了确保锥形管表面氧化膜全部去除,又不产生过酸洗现象,采用变速的方法将锥形管从酸洗槽拉出,可获得良好的表面氧化膜去除效果。

In dieless drawing process of 304 stainless steel cone-shape pipe,the thickness of oxide film and factors influencing the formation of oxide film were analyzed,and the effects of pickling temperature and pickling speed on the chemical removal process of the oxide film were studied.The results show that the oxide film thickness is gradually increased with the increase of deformation degree,the cone-shape pipe length,the induction heating temperature and the distance between hot and cold sources,and decreasing the feed speed.When the temperature of pickling solution（98% H2 SO4（80 ～ 100 mL.L-1）,NaNO3（40 ～ 50 g.L-1）,NaCl（10 ～ 20 g.L-1）,（CH2）6N4（3 ～ 5 g.L-1）） is 70 ～ 80 ℃,in order to remove the oxide film completely without excessive corrosion the cone-shape pipe is pulled out from the pickling sink at variable drawing speed,and the good surface quality of the cone-shape pipe is obtained.