Microstructures and crack resistance of armoured steel weldment by CO₂ shielded arc welding

The armoured steel welded joints were prepared by CO₂ shielded arc welding with modified H10MnSi wire and H08Mn2Si wire respectively. The microstructures of the welded joints were examined by means of Olympus optical microscope and scanning electron microscope. And the Vickers microhardness profiles were measured by Vickers microhardness tester. The crack resistance in Y-groove welded joints was also compared. The experiment results showed that the crack resistance of the welded joint using H10MnSi wire was better than that of the weldment using H08Mn2Si wire, which is mainly due to the fine crystal grain in the weld metal and the more content of acicular ferrite.