气体氮化处理后渗层深度的检验

工件进行渗氮化学热处理后，在质量检验的过程中，渗层深度是一项重要的检测指标。层深的测定有金相法和硬度法两种，硬度法为主，金相法为辅。检测所依凭的国家标准涉及比较多，在不同的场合、阶段需要查阅合乎要求的不同的标准。该文以38CrMoAIA钢齿轮气体氮化为例，详细介绍了齿轮氮化后渗层深度的检测流程。检测过程非常适合作为金相技术实践教学过程中的综合性实验项目，有助于同学更好地理解、掌握专业基础实践技能的实际应用。

Testing of Nitride Case Depth after Gas Nitriding Processing

Nitride case depth is a key indicator of quality verification for sample parts that have been processed with nitriding chemical heat treatment. Two methods can be used to test the case depth:metallographic method and hardness method,with the former supplementing the latter. There are numerous state standards involved in such testing,and various standards might be consulted and applied under different circumstances and in different stages. In this article,the gas nitriding processing of 38CrMoAlA steel gear is taken as an example to introduce the testing procedure of the case depth after the nitriding. This procedure represents a good integrated experimental program as part of the metallographic practice teaching and serves well in assisting students to better comprehend fundamental practical skills and capture its practical applications.