弹簧钢奥氏体晶粒检验方法的探讨

Discussion about the test method of austenite grain for spring steel

弹簧钢奥氏体晶粒度按照国标GB／T6394的规定采用直接淬硬法进行检验，在生产中由于试样表面经侵蚀后形成的黄色膜导致无法进行检验。尝试改进直接淬硬法和使用氧化法进行奥氏体晶粒度检验，试验表明，改进的直接淬硬法、氧化法均可显示奥氏体晶粒度，氧化法显示的晶界比直接淬硬法更清晰、完整，直接淬硬法显示的晶界勉强可作为生产评定，无法作为仲裁评定；氧化法测定的结果非材料基体组织的奥氏体晶粒度，只能表征材料的后续热处理能力。

The austenite grain size of spring steel is tested by the direct hardening method according to GB/T 0394, anct it can not be tested in the production due to the yellow film formed after the erosion of the sample surface. The direct hardening method and the oxidation method were used to test the austenite grain size. The experimental results showed that the improved direct hardening method and oxidation method can both showed the austenite grain size. The grain boundary obtained by the oxidation method was clearer and more complete, while that obtained by the direct hardening method can barely be evaluated as a production and can not be evaluated as an arbitration. And the results of the oxida- tion method were not the austenite grains size of the material matrix structure, which can only characterize the subse- quent heat treatment capacity of the material.