Secondary Hardening of an AISI M3:2 High Speed Steel Sinter 23 Hot Isostatic Pressed

摘要

The main aim of this work was to study the behavior of the secondary hardening of AISI M3:2 high speed steel named Sinter 23~® produced by powder metallurgy process of hot isostatic pressing (HIP). The M3:2 high speed steel Sinter 23~® was submitted to heat treatment of hardening with austenitizing temperatures of 1140 ℃, 1160 ℃, 1180 ℃ and 1200 ℃ and tempering at 540 ℃, 560 ℃ and finally 580 ℃. The effectiveness and response of the heat treatment was determined using hardness tests (Vickers and Rockwell C hardness) and had its property of secondary hardness evaluated. The results showed that the secondary hardening peak of Sinter 23~® high speed steel (tempering temperature at which maximum hardness is attained) is at 540 ℃ for the lower austenitization temperatures of 1140 ℃ and 1160 ℃, and it is at 560 ℃ for the higher austenitizing/quenching temperatures of 1180 ℃ and 1200℃.