Residual stresses and their effect on abrasive wear resistance of electric arc cored wire coatings

The influence of first-order stresses on the abrasive wear resistance of arc sprayed coatings (ASC) is investigated. Based on studies of their phase composition and its influence on the level of residual first-order stresses σres, an empirical formula for determining these stresses is proposed. Since not only the level of σres in the coating but also its cohesive strength σB is important for the ASC performance, it is proposed to use their ratio σres / σВ as a characteristic of the ASC cracking susceptibility. It is empirically established that when σres / σВ > 0.75, the coatings are prone to micro­cracking, and when σres / σВ > 0.85, a net­work of cracks is formed in them. Preheating the samples before ASC spraying with cored wires (CW), as well as their tempering after spraying, reduces tensile stress in the coatings, promotes the release of dispersed carbides and borides in their structure and, as a result, significantly increases their abrasive wear resistance.