Abstract In this paper, we report the study of degradation for a kind ideal mandrel material called poly-α-methylstyrene based on theoretical and experimental methods. First-principles calculations reveal two types process: depolymerization hydrogen-transfer-induced chain scission. The energy barrier former (0.68–0.82 eV) is smaller than that most latter (1.39–4.23 eV). More importantly, reacti...

This paper aims to improve the mechanical properties and fatigue life of AISI/SAE 4140 alloy steel connecting rods (CRs). Conventional CRs are typically manufactured through open die forging/hammering, blocking, hot forging processes. In present work, a modification process route has been proposed such that forging/hammering was completely replaced with multistep asymmetrical reducer rolling te...

The operation of applying riffles by local plastic forming on the inner surface a cylindrical shell with help working mandrel wedge protrusions is considered. results computer simulation are presented, and comparison made known reduction corrugation method. A significant decrease in technological force process removal using new method has been established