What are the performance characteristics of stainless steel welded pipes at low temperatures

What are the properties of stainless steel welded pipes at low temperatures? At low temperatures, the resistance, linear expansion coefficient, thermal conductivity, specific heat capacity at temperature, and magnetism of stainless steel welded pipes will undergo significant changes. The resistance and linear expansion coefficient decrease at low temperatures; the thermal conductivity and specific heat capacity sharply decrease at low temperatures; the Young's modulus (tensile modulus) increases simultaneously when the temperature drops. Because the austenitic series stainless steel pipes have the Ms point (the start temperature of martensitic transformation or the temperature at which martensite is formed) at low temperatures, when kept below the Ms point, martensite can be generated. The generation of martensite at low temperatures causes the representative steel type SUS304 (18Cr-8Ni) of the austenitic series stainless steel to be non-magnetic at room temperature but magnetic in the low-temperature environment. 

In a low-temperature environment, the deformation energy is small. The phenomenon where the elongation and the reduction of area decrease in a low-temperature environment is called low-temperature embrittlement. It usually occurs in the body-centered cubic structure of the ferrite series. 

Low temperatures are mainly related to reduced solar radiation and the application of artificial cooling sources. In the high-latitude regions of the Earth (such as the polar regions above 66.5° latitude, the Siberian region of Russia, the northeastern, northwestern and north-central regions of China in winter), solar radiation is significantly reduced; in temperate and some subtropical regions, the winter temperature can be lower than 0°C, and the relative humidity is high, making frostbite more likely to occur. Artificial cooling sources are mainly found in occupational workplaces, such as various cold storage facilities, the production, transportation and use of cooling agents. Appropriate temperature is a necessary condition for the existence of living organisms, but various organisms have very different adaptability to temperature changes. When the environmental temperature undergoes drastic changes, it can cause certain injuries or diseases. During temperature changes, low temperatures can become a cause of illness or the triggering of diseases. During low-temperature operations with stainless steel pipes, the environmental factors determine whether hypothermia occurs; the body mainly dissipates heat through evaporation, conduction and convection; and wind speed and temperature are the main factors affecting evaporative heat dissipation. The humidity in the working environment of stainless steel pipes also has a significant impact on low-temperature operations.