从腐蚀原理出发，对超超临界锅炉用P91/P92钢奥氏体晶界显示方法进行了探索研究。结果表明：采用过饱和苦味酸-十二烷基苯磺酸钠-双氧水溶液热化学浸蚀与10%（体积分数）硫酸溶液电解浸蚀相结合的浸蚀方法，可清晰显示P91/P92钢的原奥氏体晶界；P91/P92钢的马氏体晶粒度与实际奥氏体晶粒度评级结果一般相差2~4级；对于P91/P92钢应检测其实际奥氏体晶粒度。

Based on the corrosion principle, the austenite grain boundary display method of P91/P92 steels for ultra-supercritical boilers was studied. The results show that the original austenite grain boundary of P91/P92 steels can be clearly displayed by the combined etching method of chemical etching with hot supersaturated picric acid-sodium dodecyl benzene sulfonate-oxygen peroxide aqueous solution and electrolytic etching with 10% (volume fraction) sulfuric acid aqueous solution. The martensite grain size of P91/P92 steels is generally different from the actual austenite grain size by 2-4 grade. For P91/P92 steels, the actual austenite grain size should be tested.