特厚F690海工钢焊接接头的组织及腐蚀磨损研究

选择OK Tubrod 15.27S为焊丝,利用自动埋弧焊技术对厚度为80 mm的特厚F690海工钢板进行了双面多层焊接,观察了F690海工钢焊接接头的显微组织,测试分析了F690海工钢焊接接头在3.5%NaCl溶液中的摩擦磨损行为、腐蚀行为。结果表明:在焊接电流450 A、焊接速度52 cm/min条件下得到的接头组织致密,焊缝区显微组织主要由细小的板条状贝氏体和粒状贝氏体组成。在3.5%NaCl溶液中,焊缝区比热影响区表现出更好的耐磨性;焊缝区和热影响区的磨损机制与载荷大小有关,10 N时表现为磨粒磨损,20 N和30 N时表现为磨粒磨损和粘着磨损的混合磨损。与热影响区相比,焊缝区的自腐蚀电位较高、钝化区较小,耐蚀性较低。

Microstructure and Corrosion Wear Behavior of Welding Joint of Extra-thick F690 Marine Engineering Steel

With OK Tubrod 15.27S as the welding wire, double-sided and multi-layer welding was conducted by using automatic submerged arc technology for the extra-thick F690 marine engineering steel plate with a thickness of 80 mm. Then, F690 marine engineering steel welding joint was observed for its microstructural feature, and tested in a 3.5%NaClsolution to analyze its friction and wear behavior. The results show that the welding joint has a compact structure with the welding at the current of 450 A and at the speed of 52 cm/min. The microstructure of the weld zone is mainly composed of fine strip bainite and granular bainite. It is found that in the 3.5%NaCl solution, the weld zone is better than the specific heat affected zone in term of wear resistance. The wear mechanism of both the weld zone and the heat affected zone is related to the size of the load, with abrasive wear occurring at 10 N and a combination of abrasive wear and adhesive wear occurring at 20 N and 30 N. Compared with the heat affected zone, the weld zone has higher self-corrosion potential, smaller passivation zone and lower corrosion resistance.