论文部分内容阅读
采用焊接热模拟与实际焊接相结合的方法研究了焊接热循环对含铜时效钢焊接热影响区(HAZ)组织与性能的影响规律。结果表明,相同条件下模拟焊接粗晶区的低温韧性最低,硬度最高。随着t8/5的增大,粗晶区组织中板条状贝氏体数量减少,粒状贝氏体数量逐渐增多,尺寸增大,低温韧性显著降低。模拟焊接细晶区、两相区低温韧性较高,冷却速度较慢(t8/5=100 s)时其低温冲击功仍不低于200 J,维氏硬度不低于母材,表现出良好的强韧性匹配。实际焊接结果进一步表明含铜时效钢HAZ具有良好的低温韧性,在-40℃下冲击功不低于175 J,HAZ的最高硬度为249 HV,最低硬度为218 HV,与母材持平,硬化软化效果不明显。该钢具有良好的焊接性能。
The effect of welding heat cycle on the microstructure and properties of heat-affected zone (HAZ) of copper-containing aged steel was studied by the combination of welding thermal simulation and actual welding. The results show that under the same conditions, the low temperature toughness of the simulated welding coarse grain is the lowest and the hardness is the highest. With the increase of t8 / 5, the number of lath bainite in the coarse grain zone decreased, the number of granular bainite gradually increased, the size increased, and the low temperature toughness decreased significantly. In the simulated welding fine-grained region, the low-temperature toughness of the two-phase region is high, the low-temperature impact energy is still not less than 200 J when the cooling rate is slow (t8 / 5 = 100 s), and Vickers hardness is not less than that of the base metal The tough match. The results of the actual welding further demonstrate that the HAZ with copper age has good low temperature toughness with an impact energy of not less than 175 J at -40 ° C, a maximum HAZ hardness of 249 HV and a minimum hardness of 218 HV, flat with base metal, softening no significant effect. The steel has good welding performance.