Seamless Nickel-Chromium-Iron Alloy Pipes Scope: JIS G4903 in addition to carbon, steel also contains a small amount of manganese (Mn), silicon (Si), sulfur (S), phosphorus (P), oxygen (O), nitrogen (N) and hydrogen (H). These elements are not intentionally added to improve the quality of steel, but are brought in by ore and smelting process, so they are called impurity elements. These impurities have a certain impact on the properties of steel. In order to ensure the quality of steel, the chemical composition of all kinds of steel is strictly stipulated in technical standards.
