The resistance, linear expansion coefficient, thermal conductivity, mass hot-melt and magnetic properties of stainless steel pipe will vary greatly at low temperatures. The coefficient of linear expansion decreases at low temperature, and the thermal conductivity and mass heat capacity decrease sharply at low temperature, and the young's modulus (longitudinal modulus of elasticity) increases at the same time when the temperature drops. Because the austenitic stainless steel pipe has a Ms point at low temperature (Subzreo temperature) (martensite metamorphosis or martensite formation temperature), martensite can be formed when it is kept below the Ms point. The formation of martensite at low temperature makes the representative steel SUS304 (18Cr-8Ni) of austenite series stainless steel nonmagnetic at normal temperature and become magnetic in low temperature environment.
A shell applied to a freezer. Ferritic AISI 304 Seamless Stainless Steel Pipe is a body-centered cubic structure, when the material properties show weakening, sharp cracks will rapidly expand and cause brittle failure. Because austenitic stainless steel is a face centered cubic structure, brittle failure will not occur. Arcane throwing stainless steel SUS304L (18Cr-9Ni-LC) and SUS 316L (18Cr-12Ni-2Mo-LC) show superior impact characteristics at low temperatures. However, it is necessary to pay attention to the precipitation of ferrite or the precipitation of martensite due to processing, and the tendency of embrittlement caused by the sensitization of carbides or equal phases of sigma.
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