Improvement of mechanical properties of large-scale low-carbon steel cast products using spray quenching

摘要

We have revealed improvement of the mechanical properties of 20GL-type low-carbon steel solebars of freight bogies after volume-surface hardening with a fast-moving water stream (spray-quenching). Formation of a gradient structure having variable strength and toughness after volume-surface hardening to the depth up to 5-8 mm from the surface provides 1.6-1.8 times higher strength of the material as compared to a normalized condition; it also changes the fracture ldnetics under load, and increases the solebar fracture resistance under static and cyclic loading.