铸铁激光熔覆片状石墨与球状石墨应力场分析  

Stress Field Analysis of Lamellar Graphite and Nodular Graphite During Laser Cladding on Cast Iron

作　　者：范常峰 刘衍聪[1,2] 伊鹏[1] 战祥华 刘本良 

机构地区：[1]中国石油大学(华东)机电工程学院,山东青岛266580 [2]中国石油大学胜利学院,山东东营257097

出　　处：《热加工工艺》2015年第14期181-183,共3页Hot Working Technology

基　　金：国家自然科学基金资助项目(51405512);山东省自然科学基金资助项目(ZR2013EEM031);青岛市科技计划基础研究项目(13-1-4-255-jch);中央高校基本科研业务费专项资金资助项目(14CX06125A)

摘　　要：为减少熔覆开裂,进一步了解铸铁激光熔覆过程中结合区微裂纹萌生机制,基于激光熔覆三维热-力耦合模型,选取其中的单元建立石墨相微观模型,分析片状与球状石墨周围的应力特征。计算结果表明,片状石墨尖端存在较大的拉应力集中,极易导致微裂纹萌生。球状石墨周围为高应力区,微裂纹主要产生于球墨周围,相对于片状石墨,其应力约降低50 MPa,微裂纹的萌生相对减少。In order to reduce the cladding cracks and explore the initiation mechanism of microcracks during laser cladding on cast iron, based on the thermo-mechanical coupling model of laser cladding, the graphite microscopic model was built by picking specified elements, and the stress characteristic around lamellar graphite and nodular graphite was analyzed. The simulation shows that tensile stress concentration exists in the tip of lamellar graphite, which is easy to initiate the microcracks.The area around nodular is graphite high stress area, and the microcracks mainly initiate in this area. Compared with lamellar graphite, the stress around nodular graphite is 50 MPa lower, which can reduce the initiation of microcracks effectively.

关 键 词：激光熔覆 片状石墨 球状石墨 应力场 

分 类 号：TG441.4[金属学及工艺—焊接]