Solidification Cracking of IN 718 TIG Welds
Solidification cracking was observed during a tungsten–inert gas (TIG) welding process used to join two thin sheets of nickel-based superalloy IN718.Microstructural analysis of cracked specimens showed a centerline grain boundary (CLGB) susceptible to limit the hot ductility of the welds.Different welding parameters were modified to avoid the formation of the CLGB; such as the current waveform,the heat input and the welding speed.Results show that it is possible to obtain a microstructure free of a straight CLGB when using a heat input below 135 J/mm.However,to achieve full penetration,the heat input cannot be decreased below 112 J/mm.The experimental results are presented in the form of a weldability map as proposed by Dye et al.and they can be used to predict the range of process parameters favorable to successfully TIG weld IN718 sheet metal.
Fusion welding solidification cracking nickel superalloy microstructure process
Myriam Brochu Alexis Chiocca Rafael Navalon-Cabanes Jean Fournier
Department of Mechanical Engineering,école Polytechnique de Montréal,Montréal H3T 4A6,Canada Special Process Development Group,Pratt & Whitney Canada,Longueil J4G 1A1,Canada
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）