ASTM A240 Grade 409L 410S 416 420 430 436L 439 441 443 444 Stainless Steel Sheets & Coils Feature

400 Series stainless steels are iron-carbon-chromium alloys and can be both in martensitic or ferritic microstructure. Comparing with austenitic stainless steels, they have more carbon content. This provides better strength and wear resistance. Also they have generally less corrosion resistance. Martensitic stainless steels can be used in hardness required applications because they can be hardened by heat treatment.

Martensitic stainless steels are less weldable comparing with austenitic types because of their brittle structure but they can be more weldable after quench+tempering heat treatment. However, welding of high carbon content martensitic stainless steels generally is not advised.

400 Series stainless steels do not contain high nickel like austenitic types. Chromium content is generally between 13-25%. For types contains up to 0,4% carbon, are generally used in pumps, valves, shafts, fittings, flanges and others which carbon contents are below 0,4% are used in generally for cutting tools and other applications that require wear resistance.

Differences Between 300 and 400 Series Stainless Steels

· 300 Series are in austenitic microstructure, 400 Series are in ferritic or martensitic type.

· 300 Series are not magnetic, 400 Series can be magnetized.

· 300 Series have generally higher corrosion resistance rates.

· 400 Series can be hardened by heat treatment.

· 400 Series have generally higher strength and hardness.

400 Series ferritic stainless steels can content chromium up to 25-28%. These types are used for high temperature applications.

400 and 500 Series martensitic type stainless steel can be hardened by heat treatment. Therefore, they are generally used in applications that require mechanical strength and hardness. Chromium contents can be between 12-15% and additionally involves 1% Molibden.

We supply 400 Series stainless steels in below grades and in pipe, tube, fitting, flange, plate, round bar and profile forms. AISI 400 Series steels are used in silencers, agricultural equipments and tools, engine shafts, industrial valves, turbine parts, cutting tools, medical and food industry, automotive exhaust systems and other sector applications that require hardness, strength and corrosion resistance.

403: Generally used in turbine parts and the parts that exposed to high stress and abrasion.

409H: Has high corrosion resistance at high temperature levels can be used up to 600 celcius. Weldability of grade is better. Generally used in automotive industry.

409L: Weldability and formability are good and due to additional titanium, its high temperature corrosion resistance is good. 409L has ferritic microstructure and can be used up to 750 celcius. Generally used in heat exchangers and automotive parts.

410 (1.4006 - X12Cr13): This grade is in martensitic microstructure. Corrosion resistance is relatively lower. Surface of material can be hardened by heat treatment. Therefore it is generally used in parts require wear resistance in the form of pipe, fitting, valve, fasteners, turbine blades and pump parts.

410L: Weldability is better comparing to 410 grade because of its lower carbon content. It has relatively good corrosion resistance at high temperature values. 410L grades are generally used for high temp. Applications like heater/boiler parts, combustion chambers.

414: Similar with 410 grade the difference is better corrosion resistance than 410.

416: The difference from 410 grade is additional sulphur. This chemical composition makes the material more formable. It is used in fasteners, gears, mils and shafts.

420 (1.4021 – X20Cr13) : This grade is in martensitic microstructure. After quenching it reaches high mechanical strength and hardness values and material can be suitable for heat treatment. This material is widely used in processing tools, turbine blades and industrial valves.

430 (1.4104 – X14CrMoS17): This grade is in ferritic microstructure. Formability and corrosion resistance is good. It is generally used in boiler parts, food and medical industry and other sector applications that require heat resistance. For some applications it is used alternative for 304 grade due to its cost advantage.

431: Consists higher chromium, therefore has got better corrosion resistance. Widely used in industrial valves and pumps.

436L: This grade has high heat and wear resistance. Due to its Nb content formability and weldability of material is good.

440: Comparing with 410 and 420 grades, AISI 440 is more hardenable by heat treatment. Due to it has higher carbon and chromium content hardness and corrosion resistance is better. Therefore its formability is lower. This grade of materials are generally used in cutting tools, medical tools, bearing materials and die parts due to its high hardness values.