Weld Metal Dilution and Martensite Appearance in Dissimilar Metal Welding

摘要

The upper boundary for martensite apperance in stainless steel weld metals on the Schaeffler Diagram is shown to be overly conservative. It also does not predict a manganese effect beyond that given by the Nickel Equivalent. A modification to the WRC-1992 Diagram is proposed which takes variation of manganese into account. The martensite boundary is based upon magnetic measurements and 2T longitudinal face bend tests of numerous submerged arc weld overlays. Separate boundaries are offered for 1percent, 4percent, and 10percent Mn. Nitrogen up to 0.1percent and Mo up to 3percent do not require separate martensite boundaries - their behavior is correctly portrayed by the 1992 chromium and nickel equivalents. But carbn, raised from 0.1 to 0.3percent, is found to have virtually nil effect on martensite appearance (austenite stability), which has to be taken into account in using martensite boundaries.