Martensitic Stainless Steel

Martensitic stainless steel also called as hardenable stainless steel are usually with 11.5% chromium up to 18% chromium with higher level of carbon. They are capable of being heat treated to a wide range of hardness and strength level.






Corrosion resistance

AISI 410 Moderate corrosion resistantence and high mechanical properties Machines best in hardened and temperd conditions. Readily machineable with all operations such as turning, milling and reaming, etc. Welding in the hardened and tempered condition requires special attention due to its air hardening capability which can lead to the formation of brittle martensite, resulting in cold cracking due to contraction stresses within the weld and heat affected zone. Welding in the annealed condition can be beneficial in accommodating some of these contraction stresses in the base material when a high degree of restraint applies or with large sections Good corrosion resistence to air, water and some chemicals. Satisfactory corriosion resistance to nitric acid, concentradted sulphuric acid, dilute acetic acid and naptha.
AISI 420 Good corrosion resistance and increased strength and hardness Machines best in hardened and temperd conditions. Despite of consisting high carbon content is still regarded of having reasonable machineability with all operations such as drilling, turning, etc. Recommended for welding in either annealed or hardened and tempered condition. Full corrosion resistance only in the hardened or hardened and stress relieved conditions. Type 420 resists corrosion by the atmosphere, fresh water, mine water, steam, carbonic acid, crude oil, gasoline, petroleum product, perspiration, alcohol, ammonia, mercury, sterilizing solutions, soaps and other similar corrosive media.
AISI 431 High hardenability martensitic stainless steel, high strength and god corrosion resistance. Machines best in hardened and tempered condition. Readily machinable in all operations such as turning and drilling,etc. Generally not recommended for welding in either hardened or tempered condition, resulting in cold cracking within the weld and heat affected zone. Very good corrosion resistance to atmosphere, mild marine and industrial atmosphere, organic materials, nitric acid and petroleum products.
AISI 440C Good corrosion resistance, Extreme high strength hardness and wear resistance Due to high carbon content has low machinability. It machines best in fully annealed conditions. As 440c has high carbon content, Welding is not recommended in hardened and tempered condition due to its high air hardening capability. Good corrosion resistance in mild domestic and industrial environment, fresh water, organic materials, mild acid, petroleum products

Grades and Chemical Composition of Martensitic Stainless Steel

SR NO CAST Other Common designation UNS ASTM C Mn Cr Ni Mo Fe Cu P Si S N Others
1 410 S41000 A240 410 MAX0.15 1.0MAX 11.50~13.0 1.0 MAX 0.5 max 0 0 0 0
2 420 S42000 A580/A176/A276 0.15~.36 1.0max 12.00~14.00 1.0max 0 0 0.04 1.0 max 0.03
3 431 S43100 A276-98B 0.12~0.2 1.0max 15.0~18.0 1.25~3.0 0.04max 1.0max 0.03max
4 440C S44004 A276 0.95~1.20 1.0max 16.0~18.0 1.0max 0.0~0.75 0.04 max 1.0 max 0.03 max
5 F6NM J91540 A352 A487 A743 CA6NM 0.06 max 1.0 max 11.5~14.0 3.5~4.5 0.4~1.0 1.0 max

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