- Stainless steel welded pipe is brittle at low temperatures, and the deformation energy is very small in a low temperature environment. At low temperatures, the phenomenon of elongation and area shrinkage reduction is called low temperature embrittlement. Most of the ferrite series body-centered cubic structure.
- Low temperature processing welded pipe is a martensitic series stainless steel from the austenitization temperature quenching, and then cooled to low temperatures, thus by prompting the production of martensite quenching method, suitable for easy to produce residual austenite stainless steel.
At low temperatures, the electrical resistance, coefficient of linear expansion, thermal conductivity, thermal fusion quality and magnetic properties of stainless steel welded pipe can change greatly. Resistance and coefficient of linear expansion decrease at low temperatures; thermal conductivity and mass heat capacity decrease sharply at low temperatures. Young's modulus (longitudinal modulus of elasticity) increases simultaneously with decreasing temperature. Since the austenitic welded pipe has a low temperature (subzreo temperature) Ms point (martensite transformation initiation temperature or martensite production temperature), when it is kept below the Ms point, martensite can be produced. Low-temperature martensite formation makes austenitic stainless steel, steel representative steel SUS304 (18Cr-8Ni) non-magnetic at room temperature, magnetic at low temperature.
At low temperatures, ferritic stainless steel welded pipe is brittle at low temperatures like carbon steel, but not austenitic steel. Therefore, ferritic or martensitic stainless steel produces low-temperature embrittlement, while austenitic stainless steel or nickel-based alloys do not show low-temperature embrittlement.SUS410 (13Cr), SUS430 (18Cr) and so on. The impact value of ferritic steel welded pipe decreases sharply at low temperatures. Therefore, special attention is required when used at low temperatures.
