The ASTM A312 standard covers a variety of austenitic stainless steel welded pipes, and different steel grades have their own characteristics in high and low temperature environments. The following is an explanation of their performance in high and low temperature environments.

Performance in high temperature environments
Mechanical properties: Some stainless steel welded pipes in ASTM A312, such as TP310S, TP321, TP347H and other steel grades, can maintain good strength and hardness at high temperatures. They add alloy elements such as nickel, chromium, titanium, and niobium to form a stable austenitic structure, which effectively improves the high temperature strength of the steel, allowing it to withstand pressure and load at higher temperatures without deformation.
Antioxidation properties: These stainless steel welded pipes have good antioxidation properties. The chromium element in the alloy can react with oxygen at high temperatures to form a dense oxide film on the surface of the steel, preventing oxygen from further contacting the internal metal, thereby slowing down the oxidation rate and improving the steel's resistance to high temperature oxidation. For example, TP310S stainless steel further improves its antioxidation properties in high temperature environments by adding a certain amount of silicon.
Creep resistance: Some steel grades have excellent creep resistance. Under long-term high temperature, metal materials will undergo slow plastic deformation, which is creep. Some stainless steels in ASTM A312 have improved the creep resistance of the material through reasonable alloy ratio and heat treatment process, so that the pipeline can still maintain good shape and dimensional accuracy under high temperature and long-term operation conditions.

Performance in low temperature environment
Toughness: ASTM A312 stainless steel welded pipes usually maintain good toughness at low temperatures. The crystal structure of austenitic stainless steel makes it less likely to undergo brittle transformation in low temperature environments, and still has high impact absorption energy, and can withstand a certain degree of impact load without breaking, which makes them widely used in low-temperature pipeline systems, such as liquefied natural gas (LNG) pipelines.
Strength: Generally speaking, as the temperature decreases, the strength of metal materials will increase, and ASTM A312 stainless steel welded pipes are no exception. In low temperature environments, their yield strength and tensile strength will increase, but this increase in strength is not accompanied by a significant decrease in toughness, and the material can still maintain good comprehensive mechanical properties.
Corrosion resistance: Low temperature environment has little effect on the corrosion resistance of stainless steel welded pipes. At low temperatures, the chemical activity of the material decreases and the corrosion reaction rate slows down. Therefore, in some low-temperature corrosive environments, ASTM A312 stainless steel welded pipes can still maintain good corrosion resistance and ensure the safe operation of the pipeline system.