The effect of tempering temperature and microstructure on dry sliding wear behavior of quenched and tempered PM with 0.3% graphite and 1-2% Ni steels was investigated. The sintered specimens were quenched from 890℃ and then tempered at 200℃ and 600℃ for 1 hr. Wear tests were carried out on the quenched＋tempered specimens under dry sliding wear conditions using a pin-on-disk type machine at constant load and speed. The experimental results showed that the wear coefficient effectively increased with increasing tempering temperature and decreased with increasing Ni content.

The mixed atomized iron powders with 0.3% graphite and 1% Ni powders were cold pressed and sintered at for 30 min under pure Ar gas atmosphere. Some of the sintered specimens were intercritically annealed at and quenched in water (single quenching). The other sintered specimens were first fully austenized at and water quenched. These specimens were then intercritically annealed at and re-quenched in water. The experimental results showed that the wear coefficient effectively decreased in the double quenched specimen.