亚共析钢C72D2奥氏体晶粒度腐蚀剂的选用

Selection of chemical etchant for austenitic grain size of subeutectoid steel C72D2

采用直接淬硬法测定亚共析钢C72D2的奥氏体晶粒度。选用苦味酸溶液和不同配比的三氯化铁溶液作为腐蚀剂对亚共析钢C72D2进行腐蚀,观察并对比不同腐蚀剂的腐蚀效果。结果表明:用三氯化铁溶液(三氯化铁5 g+浓盐酸5滴+水100 mL)腐蚀后的奥氏体晶界比较完整,且颜色较深,便于观察和测定,可替代苦味酸溶液进行亚共析钢C72D2奥氏体晶界腐蚀。

The austenite grain size of subeutectoid steel C72 D2 was determined by direct quenching and hardening method. Using picric acid solution and ferric chloride solution of different ratio as corrosives,the corrosion effects of different corrosives on C72 D2 were observed and compared. The results showed that the austenite grain boundary of the sample corroded by ferric chloride solution(ferric chloride 5 g+concentrated hydrochloric acid 5 drops+water 100 mL)was relatively complete and dark in color,which was convenient for observation and determination. It could substitute picric acid solution for austenite grain boundary corrosion of subeutectoid steel C72 D2.