Q235钢奥氏体氮碳共渗后的回火转变

Tempering Process of Plain Mild Steel Nitrocarburized at Austenite Condition

研究了Ｑ２３５钢奥氏体氮碳共渗后共渗层回火时组织、结构、表面硬度、硬度分布以及耐磨性的变化。结果表明：奥氏体氮碳共渗层在回火后，化合物层的ε相析出γ相，奥氏体淬火层发生含氮马氏体的分解和残留奥氏体的转变，过渡层也析出了γ相，从而使共渗层的表面硬度和渗层中各层的硬度都得到很大的提高，硬度分布得到改善，同时使渗层的耐磨性提高。

In the present paper the variation of microstructure,surface hardness,hardness distribution and wear resistance of nitrocarburized layer after tempering process was investigated on a plain mild steel nitrocarburized at austenite condition The result showed that precipitation of γ ? phase from ε phase in the compound layer and from transition layer,decomposition of martensite containing N and transformation of residual austenite in the quenched layer occurred in the tempering process As a result,surface hardness and hardness of each sub layer of nitrocarburized layer were greatly increased An improved distribution of hardness was obtained and wear resistance of nitrocarburized layer was improved