Microstructural effects in wear of hardened sintered steels produced by diffusion bonded and prealloyed powders

Abstract

The influence of the microstructure on the wear behaviour of some hardened sintered steels produced with diffusion bonded powders and subjected to through hardening, carburising and sinterhardening was investigated. In dry sliding, wear was oxidative in nature and the localised surface deformation caused delamination, which further reduce the wear resistance. In these conditions, the harder the microstructure, the better the resistance to plastic strain. In lubricated rolling-sliding, wear occurs by rolling contact fatigue. Cracks nucleation was caused by the stress localisation at the pores edges. In this case, a brittle virgin martensite has a negative effect. Tempering reduces martensite brittleness, and makes its resistance to nucleation and propagation of the rolling contact fatigue comparable to that of Fe-Ni austenite.

Damage phenomena in lubricated rolling-sliding wear of a gas carburised 0.85%Mo low-alloyed sintered steel: theoretical analysis and experimental verification

“…The main damage mechanism in lubricated rollingsliding wear is the nucleation of subsurface cracks at the Hertzian depth and their propagation to the surface (contact fatigue) [1][2][3][4][5][6][7]. Moreover, in the presence of surface tensile stresses, brittle cracks may nucleate either at or close to the surface, depending on the fracture toughness of the metallic matrix [2,8].…”

Design guidelines for PM parts subject to dry rolling–sliding wear

“…10 On the other hand, in the diffusion bonded steels, the poor microhardness of the Fe-Ni areas may decrease the wear resistance. [11][12][13] The wide amount of knowledge in the literature, however, rarely shows a coherent organisation of the data, which are not systematically used in the design step.…”

“…On the other hand, in the diffusion bonded steels, the poor microhardness of the Fe–Ni areas may decrease the wear resistance 11 –. 13…”