(EN) The invention discloses a method for improving the strength and toughness of a Q890DQP steel welding joint. The method is characterized in that a low-strength matching 50 kg-grade welding wire is adopted in weld joint bottoming, welding joint filling and cover surface are subjected to welding by selecting a equal-strength matching 90 kg-grade welding wire; Ar + 20% CO2 mixed gas is adopted for protection welding, and the welding line energy is 12-16 KJ/ cm; under a middle constraint condition, non-preheating welding is adopted; and under a severe constraint condition, the preheating temperature before welding is more than 50 DEG C, and the interlayer temperature is controlled to be 100-150 DEG C. According to the method, the strength and toughness of the welding joint are improved, the welding joint can achieve the use performance matched with the master material Q890DQP, the mechanical property of the welding joint is good, the preheating temperature before welding is reduced, the production cost is reduced, the welding working environment is improved, and the production efficiency is effectively improved.
(ZH) 本发明公开了的一种提高Q890DQP钢焊接接头强韧性的方法，焊缝打底采用低强匹配50Kg级焊丝，焊缝填充及盖面选用等强匹配90Kg级焊丝施焊；采用Ar+20％CO2混合气体保护焊接,焊接线能量为12‑16KJ/cm；对于中等拘束条件下，采用不预热焊接；对于苛刻拘束条件下，焊缝焊前预热温度50℃以上，层间温度控制在100‑150℃。该方法提高了焊接接头的强韧性，使得焊接接头可达到和母材Q890DQP相匹配的使用性能，焊接接头力学性能良好，同时降低焊前预热温度，降低生产成本，改善焊接工作环境，有效提高生产效率。
