Series 400 stainless steel is an alloy of iron, carbon and chromium. It is a nickel saving stainless steel because it does not contain nickel and is also known as stainless steel. 400 series stainless steel has normal magnetic properties because it contains a martensitic structure as well as iron elements.
Series 400 stainless steels are highly resistant to high temperature oxidation and have further improved physical and mechanical properties compared to carbon steels. Most Series 400 stainless steels can be heat treated.
Composition and characteristics: commonly used 400 series stainless steel varieties are 430, 410, 420, 409L, etc., of which 430 stainless steel is the most used. 430 stainless steel chromium content of 18%, its characteristics are cheap, small coefficient of thermal expansion, resistance to chloride stress corrosion better than 300 series stainless steel varieties; but its shortcomings are also relatively obvious: forming properties, weldability and tensile strength is less than The 300 series stainless steel models, so it limits its use. 410, 420 stainless steel chromium content of 13%, their main feature is the high hardness.
400 series stainless steel in the same chromium content, in the atmosphere, fresh water and nitric acid such oxidizing media, its corrosion resistance and 300 series stainless steel, and better than 200 series stainless steel. The addition of trace elements such as niobium, titanium, copper and aluminum can improve its deep-drawn properties, weldability, corrosion resistance and high-temperature strength, and can partially replace the 300 series stainless steel.

409L stainless steel has excellent corrosion resistance, suitable for extending the life of the car and the light weight of the car, and as an environmentally friendly material that can be recycled, and other major automobile manufacturers use 100% stainless steel in the exhaust system.

410 stainless steel is a martensitic stainless steel. This stainless steel, as distinguished from 304 and 316, 410 stainless steel hardens well because of its high hardness and toughness, as well as its resistance to corrosion. The hot forcing and cold deformation properties, as well as the shock absorption properties are also outstanding, yes that’s how outstanding it is. It is also an excellent type of stainless steel and has a wide range of applications.

410S stainless steel is a non-hardening variant of type 410. The addition of small amounts of aluminum greatly reduces the formation of austenite at high temperatures, thereby limiting the alloy’s ability to harden. When the material is cooled rapidly from above the critical temperature, the result is a soft, ductile state. This non-hardening property also retards the formation of hardened cracks when the steel is welded. The alloy is fully ferritic in the annealed state. It has better toughness, plasticity and cold deformation, his rust and corrosion resistance and weldability are better than 410, 420 series, for higher toughness and impact load parts, such as automobile turbine blades, structural frame, lining, bolts, nuts, etc.

420 stainless steel is a hardenable stainless steel with good applicability, it has higher strength, hardness and wear resistance than 410 stainless steel.
In terms of applications, 420 stainless steel can be used to make cutlery, surgical instruments, scissors, etc., as well as valves, gears, shafts, cams and pivots. It can also be used to make valve parts and springs at moderate temperatures, and the material must not be used at sub-zero temperatures involving heavy stresses.

430 stainless steel is a general-purpose steel with good corrosion resistance, better thermal conductivity than austenite, smaller coefficient of thermal expansion than austenite, heat-resistant fatigue, the addition of stabilizing elements titanium, good mechanical properties of the welded parts. 430 stainless steel is used for architectural decoration, fuel burner parts, household appliances, appliance parts.

The yield strength of 444 is equivalent to 1.5 times that of carbon steel and 6 times that of glass steel, and has outstanding excellent properties for earthquake resistance, snow resistance, wind pressure resistance, impact resistance, etc. SUS444 ferritic stainless steel has a high thermal conductivity, about 130% to 150% of chromium-nickel austenitic stainless steel, which is very suitable for heat exchange applications. The coefficient of thermal expansion is small, the squad is only 60% to 70% of the chromium-nickel Olympic stainless steel, very suitable for heat up, cold shrinkage, there are thermal cycling conditions of use. The plasticity of the steel, toughness is good, suitable for stretching, rolling forming and stamping manufacturing. In particular, the application of corrosion resistance is the most excellent, in the high chloride medium corrosion resistance than ordinary ferritic stainless steel and Olympic stainless steel, generally does not produce chloride stress corrosion rupture. After the addition of Ti, Mo and other elements, improve the resistance to pore corrosion and crevice corrosion performance. The steel grade can be welded by the same method as ordinary stainless steel. This steel is especially suitable for food processing equipment, heat exchangers, water heater tanks, water reservoirs, solar collection panels, etc.