In-depth welding procedure qualification of Keyhole Tungsten Inert Gas welded high hardness grade quenched and tempered steel and dissimilar stainless steel joint

Motivated by solving the issues associated with welding of high hardness grade quenched and tempered (Q&T) steel and stainless steel dissimilar joint, such as low production efficiency and low joint efficiency, several advanced welding techniques have been introduced. However, none of them has solved the issue completely due to their respective disadvantages. Keyhole Tungsten Inert Gas (K-TIG) welding process was invented in order to provide a cost-effective and easy-to-operate keyhole mode welding process. It is much more productive and efficient than conventional multi-pass fusion welding processes. Compared with high power density (HPD) welding processes, say laser beam welding (LBW), electron beam welding (EBW) and plasma arc welding (PAW), it is cheaper, easier to operate and has much better gap bridging capability. Thus, it has great potential to be used in real fabrication and solve the issues associated with the welding of high hardness grade Q&T steel and stainless steel dissimilar joint.