Journal of Engineering Research

The hardness value of the PH13-8Mo age-hardening stainless steel bushing after aging treatment at 540℃ is approximately HRC 44.13, and the tensile strength can reach 1483.0 MPa. This is due to the precipitation of the second phase such as Ni3Al and NiAl during the aging treatment process, which plays a strengthening role. After the temperature was raised from 540℃ to 620℃, the diameter of the bushing shrank significantly, with the inner diameter shrinking by 0.133mm and the outer diameter shrinking by 0.115mm. Apart from the trace and irreversible local micro-plastic deformation of the surface material caused by stress, the main reason is that during the aging treatment process,the martensite structure transforms into reversed austenite, and the crystal structure changes. Meanwhile, reversing the presence of reversed austenite significantly reduces the strength and hardness of PH13-8Mo age-hardening stainless steel, while its plasticity is notably enhanced, with an elongation rate that can reach 19.88%.

PH13-8Mo; Age-hardening stainless steel; Aging treatment; Reverse austenite; Dimensional shrinkage