Abstract
Mechanical properties of PM alloy steels containing 5%No, 5%Ni, 5%Co and 6%Cr were investigated in order to develop an intake valve seat insert for automobile engines. After the rig wear test, corrosion test and actual engine tests, the new intake valve seat insert material was developed. The material was 5% No PM molybdenum steel made through the transient liquid phase sintering, in which the copper phase is precipitated uniformly in the matrix. This material can be used for both leaded and unleaded gasoline engines.