Compared with the physical property data of stainless steel and carbon steel, the density of carbon steel is slightly higher than that of ferritic and martensitic stainless steel, but slightly lower than that of austenitic stainless steel; the resistivity is based on carbon steel, ferrite, martensitic and The order of austenitic stainless steel is increasing; the order of linear expansion coefficient is similar, austenitic stainless steel is the highest and carbon steel is the smallest; carbon steel, ferritic and martensitic stainless steel are magnetic, austenitic stainless steel is non-magnetic, But its cold work hardening will generate magnetism when it is transformed into intensite, and heat treatment method can be used to eliminate this martensitic structure and restore its non-magnetic properties.
Compared with carbon steel, austenitic stainless steel has the following characteristics:
1) High electronegative rate, about 5 times that of carbon steel.
2) Large linear expansion coefficient, 40% larger than carbon steel, and with the increase of temperature, the value of linear expansion coefficient also increases accordingly.
3) Low thermal conductivity, about 1/3 of carbon steel.
Mechanical properties of stainless steel
Regardless of stainless steel plate or heat-resistant steel plate, austenitic steel plates have the best comprehensive properties, with sufficient strength, excellent plasticity and low hardness, which is one of the reasons why they are widely used. Austenitic stainless steel is similar to most other metal materials, its tensile strength, yield strength and hardness increase with the decrease of temperature; plasticity decreases with the decrease of temperature. Its tensile strength increases uniformly in the temperature range of 15~80°C. More importantly: as the temperature decreases, the impact toughness decreases slowly, and there is no brittle transition temperature. Therefore, stainless steel can maintain sufficient plasticity and toughness at low temperature.
Heat resistance of stainless steel
Heat resistance refers to both the oxidation resistance or gas medium corrosion resistance at high temperature, that is, thermal stability, and at the same time, it has sufficient strength at high temperature, that is, thermal strength.