The high intensity liquid phase diffused-junction coupling and the high intensity steel and the liquid phase diffused-junction mannered null mass which for liquid phase diffused junction are superior in tenacity

摘要

PROBLEM TO BE SOLVED: To provide a high strength liquid phase diffusion welded joint which is excellent in mechanical characteristics of the joint and uniformity of the structure of the jointed part when performing liquid phase diffusion welding using a high strength steel material containing 0.3% carbon and also having a tensile strength of 600 MPa with B or P as a diffusion atom, and to provide a steel material used therefor, and to provide a liquid phase diffusion welding method therefor.;SOLUTION: The high strength liquid phase diffusion welded joint is composed of: a base metal part which contains, by mass, 0.3 to 0.6% C, 0.01 to 0.5% Si, 0.01 to 3% Mn, 0.01 to 7% Cr, 0.01 to 0.7% Mo, 0.001 to 0.005% B and 0.001 to 0.01% N, and in which the content of P is limited to 0.03%, S to 0.005% and O to 0.01%, and a DT value is controlled to 10; and a jointed part which contains 2 vol.% one or more kinds selected from carboboride in which the content of B or P in the diffusion range of B or P is 0.005%, and which consists mainly of Cr and Mo with an average diameter of the equivalent sphere of 1m, BN and phosphide consisting mainly of Cr.;COPYRIGHT: (C)2006,JPO&NCIPI