Stainless Steel 1.4003 with 12% chromium in component

Stainless Steel 1.4003 with 12% chromium in component

This "utility stainless steel" is a fairly recent modification of 12% chromium stainless steel grades 409 and 410. It has been developed as a readily fabricated, low cost grade, exhibiting good resistance to wet abrasion and mildly corrosive environments. This grade is covered by Euronorm designation 1.4003 and also ASTM UNS S40977 / S41003.

Stainless Steel 304 1.4301 150mm 304L 1.4307 150mm 304H 1.4948 50mm 310S 1.4845 50mm 316 1.4401, Image source:

Corrosion Resistance of Stainless Steel 1.4003

1.4003 is effective in many applications where carbon steel, galvanised, aluminised or painted steel or aluminium give unsatisfactory life. It is not attacked by strong alkalies, and often gives adequate resistance in mildly acidic conditions. Light surface rust can form in many atmospheres, making the material unsuitable for decorative applications.

1.4003 strongly resists chloride stress corrosion cracking, but is less resistant than 304 to pitting and crevice corrosion in chloride environments. 1.4003 is likely to resist water with chloride contents of up to 100 to 200 mg/L at ambient temperatures. The presence of sulphate or nitrate ions will reduce the corrosivity of chlorides. As the grade is not stabilised it can be susceptible to intergranular corrosion in certain circumstances. Consult Atlas Steels Technical Assistance for specific environmental recommendations.

Heat Resistance of Stainless Steel 1.4003

In air 1.4003 offers scaling resistance to 620°C continuous or 730°C intermittent, but if under stress the temperature should be limited to 450°C continuous or 600°C intermittent. 1.4003 suffers negligible embrittlement after extended exposure at temperatures of 450-550°C; it can be used safely at these temperatures without loss of room temperature impact resistance.

Heat Treatment of Stainless Steel 1.4003

Annealing - heat to 700-750°C, soak for 1½ hours per 25mm section. Air cool. The maximum temperature of 750°C should not be exceeded. Annealing should usually be followed by pickling and passivating.

This grade should not be hardened by heat treatment; quenching treatments may reduce the corrosion resistance and mechanical properties.

Welding of Stainless Steel 1.4003

1.4003 can be readily welded using similar techniques to austenitic stainless steels. Low heat input processes are preferred - particularly GTAW (TIG) and GMAW (MIG). Filler wire pre-qualified by AS 1554.6 (1.4003 referred to as "4003") is grade 309, but 309L, 309Mo, 316L and 308L have been successfully used. Argon plus 1-2% oxygen shielding gases are recommended. Discolouration of the weld should be removed by pickling, except possibly in wear applications; effective purging and use of backing gases is often a better option.

Machining of Stainless Steel 1.4003

1.4003 has a machinability similar to that of grade 430, ie about 60% of that of mild steel. The work hardening rate is lower than that of austenitic stainless steels, so reducing the need for special machining techniques.

EN10088-1 Ferrite stainless steel mill

Finishes of Stainless Steel 1.4003

1.4003 is available in standard HRAP (Hot Rolled Annealed and Pickled) finish in plate, and 2B or 2D in coil.

Typical Applications of Stainless Steel 1.4003

Mining and mineral processing and transport equipment. Sugar processing equipment. Furnace and oven parts.

Specified Properties of Stainless Steel 1.4003

These properties are specified for flat rolled product (plate, sheet and coil) in Euronorm EN 10088.2 1.4003 and ASTM A240/A240M S40977 and S41003. Similar but not necessarily identical properties apply for other products (1.4003 bar is covered by EN 10088-3), but this grade is almost exclusively a flat rolled product.