Explanation

Generally, weld with weld line energy input greater than 50kJ/cm (up to 1000kJ/cm) is called high heat input welding. high heat input welding has the advantages of high deposition efficiency, fast weld speed, less weld passes, energy saving, shorter construction period, convenient operation and easy automation. It can adopt various weld methods such as gas electric vertical welding, submerged arc welding, electroslag welding, and is widely used in the construction of ships, bridges, thick wall vessels, thick wall pipelines, large steel structures and large infrastructure. However, high heat input welding is prone to significantly reduce the toughness of the weld and heat affected zone, and is prone to weld cracks. Therefore, steel for high heat input welding containing oxides or microalloyed carbonitrides that prevent austenite grain growth in the heat affected zone must be used and appropriate weld processes must be used.

Classification