气缸盖脆断裂纹分析及热处理工艺优化

Cylinder head crack analysis and heat treatment process optimization

发动机在路试过程中发生油水混合现象,泄漏检查发现气缸盖水道螺塞处产生裂纹。通过计算机辅助工程(CAE,Computeraided engineering)、力学性能、金相组织和断口等分析方法分析了裂纹产生的原因。为了减少气缸盖开裂风险,优化热处理工艺,并对优化方案进行了检验与验证。结果显示,批量生产的气缸盖综合力学性能完全满足产品质量要求,经台架试验和路试均未出现裂纹。

The engine was found that the water mixed with oil during the road test, the leakage detection showed that cracks existed near the process hole. The reasons of the craek were studied by CAE（Computer aided engineering） analysis, mechanical property test, metallography and scanning electron microscopy observation. The risk of cracks was decreased by heat treatment process optimization and process vahdation. The results show that the mechanical properties meet the requirements of production after process optimization ; cracks are not found in the bench test or road test.