不锈钢中铁素体腐蚀方法对比分析

Comparative analysis of corrosive methods for ferrite in stainless steel

铁素体作为奥氏体、马氏体和双相不锈钢的一种相组织,其含量直接影响不锈钢的焊接性、耐蚀性、力学性能和加工性,在其测定时往往由于腐蚀问题导致结果误差偏大。从检测标准出发,通过列举国内外目前针对铁素体含量及分布状态的表征方法,采用化学和电解两类方法进行铁素体腐蚀,从溶液配比、腐蚀温度、腐蚀时间、溶液可重复使用性和腐蚀效果等方面进行对比分析。结果表明:采用氢氧化钠水溶液电解铁素体整体效果较好,呈现红褐色,同时可以通过其在该溶液电解腐蚀显现的特征颜色进行该相的识别。

Ferrite is a kind of phase structure of austenitic,martensite and duplex stainless steel,and its content directly affects the welding,corrosion resistance,mechanical properties,and machinability of stainless steel. The measurement error of ferrite is usually large due to the corrosion problem. The current characterization methods for ferrite content and distribution at home and abroad were listed based on the testing standards. Two methods were adopted for the corrosion of ferrite,i. e.,chemical method and electrolytic method. The comparison analysis was conducted in the aspects of solution ratio,corrosion temperature,corrosion time,reuse of solution and corrosion effect. The results indicated that the electrolysis of ferrite with sodium hydroxide solution had a good overall effect. The sample showed a reddish-brown color. Meanwhile,the phase could be identified by its characteristic color in the electrolytic corrosion of the solution.