AUSTENITE CONTENT AND DISLOCATION DENSITY IN ELECTRON-BEAM WELDS OF ASTAINLESS MARAGING-STEEL

The volume fraction of austenite and dislocation density in electron b eam weld joints of a martensitic-austenitic age-hardenable Cr-Ni-Mo-Ti -Al stainless steel were investigated using neutron diffraction. Exper iments were performed on a high-resolution diffractometer which resolv ed microstrains of the order of 10(-4). The effect of post-weld heat t reatment on austenite content and dislocation density was investigated . As in other maraging steels, the maximum volume fraction of austenit e was obtained after quenching and intercritical annealing. Dislocatio n densities computed on the base of mean-square microstrain values wer e about 10(11) cm(-2). These densities were systematically higher in m artensite than in austenite, with very small differences between the w eld metal and base metal.