Effect of Cu{sub}3P addition on sintering behaviour of elemental powders in the composition of 465 stainless steel

摘要

The addition of Cu{sub}3P for developing the high strength 465 maraging stainless steel from elemental powders was studied. The sintering parameters investigated were sintering temperature, sintering time and wt-%Cu{sub}3P. In vacuum sintering, effective sintering took place between 1300 and 1350℃. The maximum sintered density of 7-44 g cm{sup}(-3) was achieved at 1350℃ for 60 min with 4-6 wt-%Cu{sub}3P. More than 6 wt-%Cu{sub}3P content and temperature >1350℃ caused slumping of the specimens. The sintered specimens were heat treated and a maximum ultimate tensile strength (UTS) of 767 MPa was achieved with 4 wt-%Cu{sub}3P content. The maximum hardness of 45-5 HRC was achieved in heat treated condition with 4 wt-%Cu{sub}3P content,, Above 4 wt-%Cu{sub}3P content increase in density was observed whereas the response to heat treatment decreased. Fracture morphologies of the sintered specimens were also reported. A comparison of sintering behaviour and mechanical properties of elemental powders with prealloyed powders was also given in the present study.