Factors Affecting Welding Toughness of AH36 Steel

The main factors affecting the toughness of the weld for AH36 Steel are: the chemical composition of the base metal, the plate thickness, the welding method of AH36 Steel, the welding material and the welding process, etc. After they are selected, the welding process of AH36 Steel is the main aspect that affects the toughness of the weld for AH36 Steel. When the welding heat input is increased, coarse grain boundary ferrite is formed in the weld, thereby reducing the toughness of the weld for AH36 Steel.

The toughness of the welding heat-affected zone is not adjusted and improved by adding trace elements like the weld for AH36 Steel, but is inherent in the base metal itself, which can only be improved within a certain range through some technological measures, such as using post-weld Heat treatment, reasonable selection of welding process parameters for AH36 Steel, etc. When the heat input is too large, the grains in the welding heat-affected zone will be coarsened and coarse austenite will be formed. At the same time, there will be a superheated zone with a high temperature in the heat-affected zone of AH36 Steel. The grain grows significantly and some refractory particles are melted in. The overheated and coarse austenite grains increase the stability of these refractory particles, so that the refractory particles have no time to precipitate during the cooling process of AH36 Steel and the material becomes brittle, thus reduces the toughness of the weld heat-affected zone.