Stainless Steel SUS431

Stainless Steel SUS431 is a martensitic stainless steel that offers superior strength, hardness, and moderate corrosion resistance compared to other martensitic alloys like SUS410. This alloy contains 16–18% chromium, giving it good oxidation and corrosion resistance in moderate environments. With a carbon content ranging from 0.20% to 0.30%, SUS431 is designed for applications requiring high strength, wear resistance, and the ability to withstand harsh environments, such as in the automotive, aerospace, and tooling industries.

 

SUS431 Stainless Steel Chemical Composition

Element	Composition (wt%)	Role/Impact
Carbon (C)	0.20–0.30%	High carbon content increases hardness and wear resistance after heat treatment.
Manganese (Mn)	0.60–1.00%	Improves strength and toughness, especially at lower temperatures.
Chromium (Cr)	16.0–18.0%	Provides resistance to corrosion and oxidation, enhancing durability.
Nickel (Ni)	≤0.60%	Improves formability and ductility, though lower than in austenitic grades.
Phosphorus (P)	≤0.04%	Reduces sulfur contamination and improves machinability.