On the Role of Steel Composition in High Convection Quenching

Abstract This work examines the influence of carbon and nitrogen in martensitic stainless steels on the High Convection Quenching (HCQ) behavior. The steel grades AISI 416 and 440C were investigated. High temperature solution nitriding (HTSN) was used to “alloy” AISI 416 with nitrogen. Bulk samples of 416 were examined with and without nitrogen to investigate the HCQ response. Nitrogen did not lead to a significant change of the HCQ behavior of the AISI 416 material. However, nitrogenfree AISI 416 exhibits an increased surface hardness when exposed to HCQ using water quench enhanced with ultrasound. The high carbon 440C experienced a significant suppression of the martensite start temperature when subjected to rapid cooling conditions (measured in-situ) and a significantly higher bulk hardness.