Static and fatigue strength of alloy KhN40MDTYu (�p 543) after hardening under various conditions

Abstract

1. The strength of alloy KhN40MDTYu (EP 543) can be increased substantially by high-temperature plastic deformation with final rolling temperatures at which no recrystallization occurs and aging (treatment I) or plastic deformation (10–20%) at room temperature with subsequent aging (treatment II). Treatment I is more effective. 2. Treatment I substantially increases the strength, with retention of fairly high ductility and impact strength. The fatigue strength increases approximately 100% as compared with the original quenched condition and can be additionally increased by surface hardening — shotpeening in particular. 3. Treatment II increases the strength but greatly reduces the ductility and impact strength at all degrees of deformation tested. In this case there is an optimal degree of deformation (10–20%) at which the fatigue strength reaches its maximum value. Aging increases the strength after prior deformation of 15–20%, but lowers the strength after larger deformations.