Characterization and processing

Martensitic stainless steel (such as 420, 440 series) is characterized by high carbon content, high hardness and wear resistance through heat treatment, but significant work hardening. After cold rolling need to anneal to eliminate internal stress, annealing temperature is usually controlled above the martensite phase transition point (such as 430 stainless steel annealing temperature of about 850 ℃), and by cooling to prevent martensite regeneration.

Typical grades and applications

AISI 420/440 series: Used in high strength scenarios such as cutting tools and medical equipment. For example, 440C has high carbon content (0.95%~1.20%) and hardness up to HRC 58 or above.

Annealing process: the use of full hydrogen hood annealing furnace can be oxidized, eliminating the need for pickling process and improving the surface finish.