An investigation was carried out to determine the impact strength and the fracture toughness of the multipass submerged arc (SA) weld metal of A533 grade B (20MnMoNi55) composition using Charpy V-notch and precracked Charpy-type specimens. The experimental results show that there is no large difference between the micro-hardness measured in the primary and secondary zones of the SA weld metal. The Charpy V-notch impact and fracture mechanics tests yield similar results in the primary and secondary zones. Nearly all specimens investigated exhibit the phenomenon of crack jump (“pop-in” of the load), that is, sudden cleavage or quasicleavage often followed by arrest of the crack.

A systematic experimental investigation was performed to study the residual stress, microstructure and work hardening on the wear properties of induction-hardened medium carbon steel. The dry sliding wear tests were performed using a reciprocating ball-on-flat apparatus under normal loads of 20, 50, and 100 N against ceramic ball counterface, respectively. The wear mechanism was mainly abrasive wear at low load (20 N) and delamination wear at higher load (100 N) as evidenced by the worn surface topography and wear debris. The deformation layer generated by friction work hardening reduced the friction coefficient, exhibited better antifriction. Typically, the high compressive residual stress could improve the wear resistance by delaying the propagation of microcrack and inhibiting the delamination.