Selection of Optimum Welding Condition and Evaluation of Joint Performance Using Friction Welding Behaviours. Study on Optimization of Welding Condition and Joint Properties in Friction Welding (2nd Report)

This paper discussed the posibility of selection of optimum welding condition by adopting the estimating equation for welding consisting of some welding behaviours to responce surface method using a 12 mm diameter SUS304 stainless steel. First, by analysing the relation between the welding behaviour and the tensile strength of welded joint using multiple regression analysis, an estimating equation for welding capable to estimate non-destructively was obtained. Next, by setting up the joining evaluation value obtained by the estimating equation for welding as a dependent variable and the welding condition as an independent variable, the optimum welding condition was selected using the responce surface method, namely, the posibility of selection of optimum welding condition without tensile strength was confirmed.The optimum welding condition obtained was the friction pressure P1=30 MPa, the upset pressure P2=170 MPa, the friction time t1=3.5 s and the rotating speed N=2425 rpm, and the joint efficiency was 102% with a satisfaction.