Stainless acid-resistant steel pipe (referred to as stainless steel) has low resistance to air, water, acid, alkali, salt and other media. Some of these stainless steels also resist corrosion in highly corrosive media such as acid-resistant steel pipes. In addition to good corrosion resistance, the stainless steel tube also has good low temperature properties, that is, it has sufficient toughness at lower temperatures. Due to the above characteristics, stainless steel pipes are widely used in chemical, medical equipment, light industrial products, instrumentation and marine aviation industries. At the same time, for the components working in high temperature (500 ~ 600 ° C), corrosive medium (gasoline, alcohol, oxidizing gas), different types of stainless acid-resistant steel pipes can be used. For example, jet engine intake guide vanes, Compressor blades, tail cones, and reservoirs for liquid oxygen (-183 ° C or less).

Heat-resistant stainless steel pipe, referred to as heat-resistant stainless steel pipe, is used to manufacture parts that are used for a long time at high temperatures. The strength of the steel pipe decreases as the use temperature increases, and is easily oxidized and corroded at high temperatures, causing damage to the parts. Therefore, the basic requirements for heat-resistant stainless steel pipes are: resistance to creep and breakage at high temperatures, and oxidation resistance. According to the industrial use, the heat-resistant stainless steel pipe is divided into, it is suitable for use in the case of 900~1100 °C or less, and it is not suitable for the skin steel. It is suitable for use under 650-800 °C and has no skin and has A sufficient strength is called a heat resistant stainless steel tube. The heat-resistant steel has a low carbon content, generally in the range of 0.08 to 0.15%. The main alloying elements are chromium and silicon, and some steels also contain aluminum, vanadium, nickel, titanium, aluminum, tungsten and other elements.