【摘要】 在激光功率10 kW、焊接速度20 mm/s、离焦量+10 mm的试验条件下，对10 mm厚的X65管线钢板进行激光对接焊，研究焊接接头的显微组织、力学性能和耐腐蚀性能。对试样的基体、焊缝区与热影响区的微观组织进行观察，利用硬度仪对试件进行硬度测试，并对焊缝和母材进行了电化学腐蚀试验。结果显示：焊接接头横截面呈“酒杯状”的宏观形貌，焊缝成形连续饱满，无明显缺陷。焊缝区组织主要为板条马氏体，具有最高的硬度值，热影响区的硬度次之，基体的最小；焊缝的耐腐蚀性要低于母材的，这是由于焊缝区马氏体的位错密度大，更容易被腐蚀。更多还原

【Abstract】 The laser butt welding of 10 mm thick X65 pipeline steel plate under the laser power of 10 kW, welding speed of 20 mm/s and defocusing amount of +10 mm was carried out, and the microstructure, mechanical properties and corrosion resistance of the welded joint were studied. The microstructure of the matrix, weld zone and heat affected zone of the sample were observed. The hardness test of the specimen was carried out by hardness tester. The electrochemical corrosion test of the weld and base metal was also carried out. The results show that the section of the welded joint presents the macroscopic morphology of "glass shape", and the weld forming is continuous and full without obvious defects. The microstructure of the weld zone is mainly lath martensite, and the weld zone has the highest hardness value, followed by the heat affected zone, and the matrix has the lowest hardness value. The corrosion resistance of the weld is worse than that of the base metal. Due to high dislocation density of martensite in the weld zone, the weld zone is more prone to corrosion.更多还原