SS 441 stainless steel is double balanced out ferritic hardened steel with a chromium content of up to 18% and low carbon. 441 stainless steel has better high temperature strength as compared to grade 409L in addition to 439 great resistance in various exhaust gas conditions and better oxidation resistance at elevated temperatures.
SS 441 or UNS S44100 is ferritic stainless steel with niobium providing the steel good oxidation and corrosion resistance. SS 441 is resistant to corrosion in solutions of various halogen-free organic and inorganic compounds when tested in a wide temperature and concentration range.
With its titanium and niobium content, the risk of sensitization for intergranular corrosion is reduced enough when compared to grades with non-stabilized ferritic stainless steels. It can surpass many sufficiently diluted organic and mineral acids considering the temperature and concentration of the solution.Chemical composition 441 stainless steel
|Max||18.5||1||0.03||1||0.015||1||0.03||(3xC+0.30) to 1.00||0.6||BALANCE|
SS 441 steel has corrosion resistance as 18 Cr-Cb stainless steel. Being an 18% chromium alloy, SS 441 has extra-ordinary corrosion resistance when compared to standard type 409 (with 11% chromium content). SS 441 shows similar cyclic oxidation resistance when we compare it with 18 Cr-Cb stainless but improved properties as compared to type 409, 439, 439 low titanium grade stainless steel.
Fabrication and Heat Treatment
SS 441 or UNS S44100 can be worked upon with typical forming processes like folding, bending, and drawing, etc. When we compare SS304 Vs SS 441, SS441 comes with slightly higher proof strength than regular austenitic SS 304 in combination with lower work hardening.
|SS 441||S41100||A 312, A213, A249, A 240|
SS 441 can be used in the temperature range where chromium carbides would precipitate in non-stabilized ferritic grades. The maximum service temperature of SS 441 in dry air is 950°C. Due to the stabilization of titanium, it has excellent deep-drawability.
|Grade||Density (g/cm3)||Elastic Modulus (GPa)||Co-eff of Thermal Expansion (μm/m/°C)||Thermal Conductivity (W/m.K)||Electrical Resistivity (Ωmm2/m)|
SS 441 can be stabilized both with niobium and titanium that provides good weld ductility and resistance to corrosion caused due to intergranular process in the weld heat-affected zone, which can be worked using a wide range of roll forming, mild stretch-bending or common drawing operation.
Traditional welding methods and filler materials used with austenitic 300-series can be used. Heat input while welding should be kept to a minimal level. Welded structures usually show lower ductility as compared to that of the base material.
Applications of SS 441
SS 441 or UNS S44100 grade can be used in all annealed, cold-formed, or as-welded conditions in applications where other austenitic stainless steels like Type 304/304L and Type 430 are used. Type 441 is better than Type 409 in both oxidation and corrosion resistance and usual applications of SS 441 material like 441 stainless steel sheet are automotive manifolds and exhaust system components.
Some other applications of SS 441 are:
- Indoor cladding
- Restaurant equipment and appliances
- Heat exchangers
- Catalytic converter shell
- Wall panels and cladding
- Exhaust system parts