摘要
采用宽光束ＣＯ２ 激光，对灰铸铁进行相变硬化和熔凝强化处理，分析了两种工艺条件下铸铁组织强韧化机理．结果表明，相变硬化马氏体形态主要为针状，组织内存在微细孪晶结构；熔凝形成的莱氏体组织内弥散分布着未熔Ｆｅ３Ｃ及新生相Ｆｅ７Ｃ３ ．声发射试验表明，灰铸铁经相变硬化处理，其强韧性稍优于熔凝处理的结果．结合激光形成的温度场特点，对试验结果进行了讨论．研究方法包括透射电子显微镜、Ｘ射线衍射、声发射试验等．
The microstructure and strengthening toughening mechanism of grey cast iron after wideband laser surface strengthening are investigated.The hardened microstructure is mainly composed of martensite,which features the needle morphology and twin crystal;while the result of the remelting process is fine ledeburite,with the distribution of Fe 7C 3 along the crystal boundaries.The acoustic emission test reveals that the hardened cast iron shows higher toughness than that of the remelted iron.Next,the results above are discussed with the theory of laser heating.Measures employed include:transmission electron microscope,X ray diffraction,acoustic emission,etc.
出处
《天津大学学报》
EI
CAS
CSCD
1999年第6期754-757,共4页
Journal of Tianjin University(Science and Technology)
关键词
表面强化
显微组织
强韧性
铸铁
激光处理
laser surface strengthening microstructure strength and toughness
