L'amélioration et la recherche de nouveaux matériaux résistant à l'abrasion^*

Improvement of, and research into new abrasion resistant materials

Climax Molybdenum S.A., France

Abstract

In grinding equipment, ferrous alloys with the highest carbon content have the best abrasion resistance, but, because of the severe stresses undergone in service, the material should have sufficient toughness to avoid failures.

Unalloyed or low alloy iron-carbon alloys already have a low toughness in the martensitic condition with carbon contents starting from 0.4 %, and their toughness is very low in the case of hypereutectoid steels and white irons because of the morphology of the cementite that they contain. If alloy elements are added in sufficient quantities, carbides of a different type to cementite can be obtained, which have a higher hardness, thus enhancing the abrasion resistance. These carbides also have a morphology which is more favourable for the toughness. Alloys produced according to this principle, such as high chromium white irons, may be further improved.

The possibilities for improving work-hardenable austenites have not yet been exhausted, not to mention the conventional austenitic steels with 12 and 6 % of manganese.