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.
出处
《热加工工艺》
CSCD
北大核心
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)
关键词
激光熔覆
片状石墨
球状石墨
应力场
laser cladding
lamellar graphite
nodular graphite
stress field
