Weldability of steel

The weldability of steel is affected by the carbon content and alloying element content. When the carbon content is 0.12% ~ 0.20%, the welding property of carbon steel is better. When the carbon content exceeds the above range, the weld and the heat affected zone are easy to become brittle. Generally Q235A has a higher carbon content, and the carbon content is not used as a delivery condition, so this grade is usually not used for welding components. The carbon content of Q235B, Q235C and Q235D is controlled within the above suitable range, and it is a common carbon grade suitable for welding. In high strength and low alloy steels, low alloy elements mostly have adverse effects on toughness.

The weldability of steel is not only directly related to the carbon equivalent of steel, but also related to the thickness of base material, welding method, welding process parameters and structural form. At present, the method of weldability test is used at home and abroad to check the weldability of steel, so as to formulate the welding procedures and processes of important structures and components.