Introduction Martensitic Stainless Steels
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- harris
- Issue Time
- Aug 21,2020
Summary
Introduction Martensitic Stainless Steels
Martensitic stainless steels are characterized by high strength and hardness in the heat treated condition. We offer a range of martensitic stainless alloys which contain 11 – 17% chromium with 0.15 – 0.63% carbon. Martensitic grades are magnetic in both the annealed and hardened (heat treated) condition. Our martensitic stainless steels are supplied in the as-annealed condition, ready for blanking, bending and forming followed by heat treatment to obtain customer specific properties. We produce eight martensitic grades tailored for a variety of property requirements and applications.
Applications for the martensitic stainless steels include cutlery, cookwear, surgical and dental instruments, springs, scissors, industrial blades, vehicle stampings, screwdrivers, pliers, and staple guns.
Corrosion Resistance
Heat treated martensitic stainless steels provide good corrosion resistance in many environments, particularly interacting with food acids. All martensitic stainless steels should be used in the hardened, or hardened and stress relieved, condition in order to maximize the corrosion resistance. In the as-annealed condition, martensitic stainless steels are prone to intergranular corrosion and overall exhibit poor corrosion performance.
Formability
Martensitic stainless steels can be moderately cold formed with increasing difficulty as the chromium and carbon increases. These alloys should be formed in the as-annealed condition for maximum softness and ductility.
Weldability
The martensitic class of stainless steels has limited weldability due to its hardenability. Special consideration may be required to avoid cold cracking by preheating. Post-weld heat treatment should be considered to achieve required properties. Alloys falling into the Type 420 and Type 440A families are generally considered to have poorer weldability than Type 410. The higher carbon contents of the Type 420 and Type 440A require both preheat and post-weld heat treatment.