Welding performance of UNI Fe 510 D2K1 weathering steel

Because weathering elements such as Cr, Ni, and Cu are added to UNI Fe 510 D2K1 weathering steel, the carbon equivalent is high, and the weldability of UNI Fe 510 D2K1 weathering steel is worse than ordinary bridge steel, and welding cracks, pores, slag inclusions, etc. are prone to occur defect. In accordance with the provisions of CB/T4364-2013 "Test Method for Welding Cracks in Inclined Y-shaped Groove".

The welding preheating temperature of UNI Fe 510 D2K1 weathering steel with different thicknesses is determined through experiments. In order to improve the fluidity of the weld metal, the preheating temperature and the interlayer temperature are increased by 20~40°C compared with ordinary bridge steel, so as to prolong the liquid residence time of the molten pool. Inclusions and pores are easier to discharge, and the sensitivity of weld cracks is reduced, which effectively reduces the risk of cracks in fillet welds under multi-directional heat dissipation conditions. During the welding process of UNI Fe 510 D2K1 weathering steel, strictly controlling the preheating temperature and interpass temperature can effectively improve the metallurgical quality of the weld.

Since UNI Fe 510 D2K1 weathering steel is sensitive to heat input and the welding process window is narrow, excessive welding heat input will lead to a sharp increase in the tendency of local coarse-grain embrittlement in the welding heat-affected zone. The control range of welding heat input is determined by physical simulation technology to ensure the performance of the welding heat-affected zone of UNI Fe 510 D2K1 weathering steel.