The effect of hardness and microstructure on the abrasion resistance of medium carbon Cr-Mo steel which was quenched and tempered at various temperatures was studied. Special emphasis was placed on the effect of the tempering temperatures.
A controlled dry wear tester manufactured to simulate the abrasive condition was used to measure the unlubricated wear rates of the steel abraded by alumina grinding wheel. Wear conditions were controlled after an initial wearing-in period.
Measured wear weight was converted to wear rate per unit sliding distance and unit applied load which is linearly proportional to bulk hardness and hardness of abraded surface, and also existed simple relationship between them.
In the cutting action of the abrasive particles into the metal surface, the rake angle was found to be about -18˚- -51˚ and abrasive wear constants about 0.04 - 0.15. The results closely corresponds to the results by J. Larsen-Badse, Rabinowicz et al.
The martensitic structure of the steel tempered roughly at 200℃ shows excellent high stress abrasion resistance.
The assumption on wear theory that wear weight is directly proportional to the applied load and sliding distance was confirmed by the present investigation.
중탄소 Cr - Mo 강을 소입한후 tempering 처리한 다음 abrasion resistance 에 대한 경도 및 미세조직의 효과를 연구하였다.
마모시험은 마모조건에 적합한 마모시험기를 제작하여 alumina grinding wheel 에 의해 마모된 강의 마모감량을 측정한 다음 단위마모거리당, 단위작용하중당의 마모율로 환산하였다.
마모율은 표면경도 및 bulk 의 경도에 직선적으로 비례하였으며 표면경도와 bulk 의 경도는 간단한 관계를 나타내었다.
금속표면위에서 abrasive particles 에 의한 metal cutting action 이 일어날 때 rake angle 은 대략 -18˚ ~ -51˚ 의 값을 가지며, abrasive wear constant 는 0.04 ~ 0.15 의 값을 나타내어 J. Larsen-Badse, Rabinowicz 등의 결과와 잘 일치하였다.
이 강을 대략 200℃ 정도의 온도에서 tempering 처리하여 얻은 martensite 조직은 high stress abrasion resistance 가 대단히 좋을 것으로 생각된다.
또한 마모감량이 작용하중 및 마모거리에 비례한다는 일반적인 마모이론의 가정이 본 실험에 의해 확인되었다.
