Strengthening of High-Alloy Steel through Innovative Heat Treatment Routes

Heat treatment route is an important route for the development of high-strength alloy steel. Many heat treatment processes are applied depending on alloy compositions and desired mechanical properties. There are various high-strength alloy steels, namely, austenitic stainless steel (16–26 wt%Cr, 0.07–0.15 wt%C, 8–10 wt%Ni, rest Fe), where the heat treatment adopted is the low-temperature plasma nitriding so as to achieve a strength in a range of 800–1000 MPa. In twinning-induced plasticity (TWIP) steel (>20 wt%Mn, <1 wt%C, <3 wt%Si,