400 MPa级超级钢专用焊条

Special-purpose electrode for 400 MPa grade ultrafine grained steel

焊缝金属的强韧化是超级钢焊接中的一个技术难题,要实现焊缝的强韧化,并避免冷裂纹,需开发与母材性能相匹配的焊接材料。对400 MPa级超级钢主要通过合金化控制焊缝组织使其获得针状铁素体即可获得理想的强韧性。通过大量工艺试验研究,结合400 MPa级超级钢的组织性能特点,研制开发了一种400 MPa级超级钢专用焊条。检测结果表明,该种焊条形成的焊缝金属组织为细小针状铁素体,焊缝金属屈服强度为435 MPa,抗拉强度为612 MPa,冲击吸收功为148J,其组织和性能同400 MPa级超级钢能很好的相匹配,达到了预期目的。

The strengthening and toughening of weld metal is a technical difficulty of ultrafine grained steel welding, and it needs to develop a kind of welding material matching the base metal in order to realize the strengthening and toughening of welded joint and avoid the cold crack. The ideal strength and toughness can be obtained by alloying mathod and controling weld structure to obtain the acicular ferrites. Through experiments, and unifying the microstructure and mechanical properties characteristics of 400 MPa grade ultrafine grained steel, a special-purpose electrode of 400 MPa grade ultrafine grained steel was develeped. The examination results show that, the microstructures of weld metal by this electrode are tiny acicular ferrites, and the yield strength and teusile strength of the welded joint are 435 MPa and 612 MPa, respectively. The impact absorbing energy is 148 J. Its microstructures and mechanical properties match the 400 MPa grade ultrafine grained steel well, and achieve the anticipated goal.