The high intensity, high tenacity, the alloy steel powder for the high order accuracy part, and production manner null of the sintering alloy steel which uses

摘要

PURPOSE:To give high strength and high toughness and to reduce dispersion of dimensional variation at the time of heat treatment by sticking graphite powder to steel powder with specified contents of Ni, Mo and C, forming, sintering and applying quenching and tempering treatment. CONSTITUTION:The alloy steel powder having composition of 0.5-3.5wt.% Ni, 0.7-3.5% Mo, 0.3-0.8% C and the balance of substantially Fe, is manufactured. C in the alloy steel powder is stuck on surface of steel powder particles with eutectic material of lubricant and binder in the form of graphite powder. To this alloy steel powder, one or more times of the formings and one or more times of the sinterings are executed. To this sintered alloy steel, the quenching and annealing treatments are applied. This alloy steel is available to machining parts for car needing the high strength, high toughness and high accuracy.