Internationally known as: 321, UNS S32100, TP321, SUS321, 1.4541
Executive standard: ASTM A240/ASME SA-240, ASTM A276, ASTM A182/ASME SA- 182, ASTM A312/ASMES A312
Major components: carbon (C) ≤ 0.08, manganese (Mn) ≤ 2.0, nickel (Ni) 9.0 ~ 12.0, silicon (Si) ≤ 1.0, chromium (Cr) 17.0 ~ 19.0, sulfur (S) ≤ 0.030, phosphorus (P) ≤ 0.035, titanium (TI) 5C ~ 0.7
Physical properties: 3.0, 3.0 and 3.0, 3.0 and 4.0, 3.0 and 5.0.
Physical properties: 321 stainless steel density: 7.98g/cm3
Mechanical properties: tensile strength: σb ≥ 520Mpa, yield strength σb ≥ 205Mpa: elongation: δ ≥ 40%, hardness ≤ 187 (HB)
Corrosion resistance and the main use of the environment:
321 stainless steel is Ni-Cr-Mo type Austenitic stainless steel, its performance is very similar to 304, but due to the addition of titanium, so that it has a better resistance to grain boundary corrosion and high temperature strength. Due to the addition of titanium, it effectively controls the formation of chromium carbide.
321 austenitic stainless steel has good corrosion resistance in the atmosphere, is widely used in petrochemical, electric power, bridges and automotive industries. But stainless steel "stainless" is not absolute, due to the special service environment, stainless steel corrosion will occur. Medium concentration, pH value, temperature and other factors will have a greater impact on the corrosion resistance of stainless steel. For example, in the 450 ~ 850 ℃ sensitization temperature range for long-term use, stainless steel will occur intergranular corrosion. The mechanism is that C and Cr bonding at the grain boundary, the formation of Cr23C6 and precipitation, so that the Cr content at the grain boundary is reduced, which is the so-called "chromium depletion". And Cr element is to inhibit intergranular corrosion of one of the main elements, when the grain boundary at the Cr content of less than 12%, the chance of intergranular corrosion will become greater.
Applications include: equipment for the oil and gas industry; offshore platforms, heat exchangers, underwater equipment, fire-fighting equipment; chemical processing industry, vessels and pipelines; desalination, high-pressure RO equipment and submarine pipelines; energy industry, such as power plants, desulfurization and denitrification FGD systems, industrial scrubbing systems, absorption towers; mechanical components (high-strength, corrosion-resistant, wear-resistant components).