Intensive quenching Part 2 – Formation of optimal surface compressive stresses

Abstract

In Part 1 of this series, an overview and process description of intensive quenching was provided. Generally, it was shown that intensive quenching processes typically involve cooling rates significantly in excess of even those traditionally exhibited by brine and caustic solutions and that these processes, which may involve time quenching, are conducted in a manner that yields optimal surface compressive stresses. The formation of such stresses not only substantially improves fatigue and impact strength properties, but also yields reduced propensity for cracking and deformation. In this paper, the metallurgical processes that are involved in the formation of these surface compressive stresses, which typically exceed even those formed by induction hardening and carburising, will be described.

Keywords:

• HEAT TREATMENT
• HARDENING
• INTENSIVE QUENCHING
• COMPRESSIVE SURFACE RESIDUAL STRESS