An investigation on SA 213 tube to SA 387 tube plate with backing block arrangement in friction welding process

In the present study, friction welding is carried out to weld two dissimilar materials of SA 213 tube to SA 387 tube plate using an external tungsten carbide tool to enhance and validate the mechanical and metallurgical properties. The two optimizing techniques are Taguchi L9 orthogonal array and ANOVA method for obtaining the optimal joint strength from process parameter respectively and for obtaining the maximum welding joint strength with output parameter of compressive strength. Then it is followed by the micro structural studies to reveal about the welding configuration which is capable of producing defect-free welds. In addition, hardness and compression strength of welds were obtained with nine different work pieces with various conditions. The two kinds of materials are taken in this investigation, where type 1 is tube without hole and type 2 is tube with hole on its circumference. It was observed that the optimal joint strength for the work piece without hole and with hole is 2980 MPa and 2680 MPa, respectively. The value of Vickers hardness test was found in the welded zone to be much greater in work piece without hole that the work piece with hole is 292 Hv and 217 Hv, respectively.