激光硬化合金铸铁活塞环的显微裂纹

The microcrack on the laser hardened piston ring of alloy Cast-iron

本文在激光硬化合金铸铁活塞环显微裂纹深入研究的基础上提出在活塞环激光热处理过程中,除热应力、组织应力等以外,附加于活塞环表面的切向拉应力是导致激光硬化带熔化区表面裂纹规律分布的主要原因。运行21×10~4km后的φ207活塞环证明这类径向裂皱对其服役无害,尽管在电子显微镜下观察发现有应力腐蚀微裂纹和非晶体学疲劳纹的存在,但在光学显微镜下检查未见初始裂纹的扩展。

On the base of the studying the microcrack on the surface of laser hardened piston ring this article indicate that attached tangential stretching stress in the course of laser heat treatment mainly leads to the microcrack on the laser hardened zone of the piston ring except for structural stress , thermal stress and so on. The φ207 laser hardened piston ring after testrun through 21×104 KM proved this radial microcrack is harmless because the extension after testrun of 21×104km was not discoverde under the optical microscope, even though by the electron microscope the corrosion stress microcrack and non-crystallogy fatigue beach was found out.