Under the condition of containing other elements, the formation of intermetallic compounds insoluble in solid/soluble or partially soluble in solid/soluble, so that the plasticity of the metal is reduced, so the plasticity of the alloy is poorer than that of the pure metal or single-phase solid/soluble. Next we introduce you to the role of alloying elements in the composition of spiral submerged arc welded steel pipe:
Iron (Fe): is the basic metal element of stainless steel plate;
Chromium (Cr): is the main ferrite-forming element, chromium and oxygen combination can generate corrosion-resistant Cr2O3 passivation film, is one of the basic elements of the stainless steel plate to maintain corrosion resistance, chromium content can be increased to improve the passivation film repair capacity of steel, general spiral submerged arc welded steel pipe chromium content in more than 18%;
Carbon (C): is a strong austenite-forming elements, can significantly improve the strength of steel, in addition to carbon on corrosion resistance also has an adverse effect;
Nickel (Ni): is the main austenite-forming elements, can slow down the corrosion phenomenon of steel and grain growth during heating;
Molybdenum (Mo): is a carbide-forming element, the formation of carbide stability, can prevent austenite heating grain growth, reduce the sensitivity of the steel overheating, in addition to molybdenum can make the passivation film is more dense and solid, thus effectively improving the resistance of the stainless steel sheet of Cl-corrosion;
Niobium, titanium (Nb, Ti): is a strong carbide-forming elements, can improve the intergranular corrosion resistance of steel. However, titanium carbide has an adverse effect on the surface quality of spiral seam submerged arc welded steel pipe, so in the higher surface requirements of the stainless steel plate is generally improved by adding niobium to improve performance.
Nitrogen (N): is a strong austenite forming element, can significantly improve the strength of steel. However, it has a greater effect on the ageing cracking of stainless steel plate, so the nitrogen content should be strictly controlled in the stainless steel plate for stamping purposes.
