论文部分内容阅读
采用Gleeble 3800试验机模拟60 mm特厚高强韧桥梁钢板热影响粗晶区(CGHAZ)的焊接热循环,通过金相分析、硬度测试和示波冲击试验研究了焊接热输入量E、二次峰值温度TP2对CGHAZ显微组织与性能的影响。结果表明,单道次焊接热模拟工艺条件下,随着焊接热输入量的增大,一次粗晶区(CGHAZ)组织由细板条贝氏体(LB)逐渐转变成粒状贝氏体(GB),而冲击吸收能量和显微硬度值随着焊接热输入量的增大而减小;焊接热输入量不大于50 k J/cm时,试验钢板具有较好的冲击性能,M-A组元粗化,冲击性能下降。在双道次焊接热模拟工艺条件下,E=30 k J/cm时,冲击吸收能量随着TP2的增大呈现出先上升后下降的趋势;TP2=750℃时,冲击性能最差,表现出临界粗晶热影响区脆化。
The welding heat cycle of CGHAZ in 60 mm thick high strength and toughness bridge girder was simulated by Gleeble 3800 test machine. The heat input E, the secondary peak value Effect of temperature TP2 on the microstructure and properties of CGHAZ. The results show that CGHAZ gradually changes from thin slab bainite (LB) to granular bainite (GB) under single-pass welding thermal simulation process with increasing welding heat input ), While the impact energy and microhardness value decrease with the increase of welding heat input. When the welding heat input is less than 50 kJ / cm, the test steel plate has better impact performance, The impact of performance degradation. Under the condition of E = 30 kJ / cm, the energy of impact absorption increased firstly and then decreased with the increase of TP2 under the condition of E = 30 kJ / cm. Under the condition of TP2 = 750 ℃, the impact performance was the worst Critical coarse heat affected zone embrittlement.