Technical Manual for S31050 Stainless Steel Bars

S31050 bar is a high-performance duplex stainless steel material, combining the advantageous characteristics of both austenite and ferrite phases. The precise ratio of chemical components, including chromium (24-26%), nickel (6-8%), and molybdenum (3-4%), endows the material with outstanding corrosion resistance, particularly in chloride environments, with outstanding resistance to pitting and crevice corrosion. The density of the bar is approximately 7.8g/cm³, and its tensile strength exceeds 650MPa, with an elongation rate of over 40%. It combines high strength with good plasticity. During processing, attention should be paid to its work hardening tendency, which can be restored through intermediate annealing. It is mainly applied in chemical equipment, marine engineering, and energy fields, and is suitable for manufacturing high-stress components such as shafts and fasteners.

The welding performance of S31050 bar is excellent. It is recommended to use ER2594 welding wire for the matching process. The preheating temperature should be controlled at 150-200℃ to reduce the risk of hot cracking. Its thermal expansion coefficient (17.5×10⁻⁶/℃) lies between that of carbon steel and pure austenitic stainless steel, which can effectively alleviate thermal stress deformation. The heat treatment should adopt a 1050-1100℃ solution treatment followed by rapid water cooling to balance the two ratios. This material also has good low-temperature toughness, maintaining an impact energy of ≥50J at -50℃, and is suitable for low-temperature scenarios such as LNG storage and transportation.
The S31050 bar material continues to be highly popular in the Chinese market, thanks to its high cost-effectiveness and localized supply advantages. With the rapid development of domestic industries such as chemicals, marine engineering, and new energy, this material, due to its excellent corrosion resistance and mechanical properties, has become a popular alternative to imported high-end stainless steel. The annual growth rate of purchases in industrial-intensive regions such as East China and South China exceeds 15%. Enterprises like Baowu Tisco have achieved large-scale production, further promoting its market penetration.