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研究了不同焊接热输入下机械振动加速度对Q345B钢焊接接头力学性能和显微组织的影响。结果表明,在同一机械振动加速度下,焊接接头的屈服强度从大至小的焊接热输入依次为:22.8kJ/cm>26.6kJ/cm>31.6kJ/cm,焊接接头的断后伸长率从大至小的焊接热输入依次为:31.6kJ/cm>26.6kJ/cm>22.8kJ/cm。当焊接热输入为26.6和31.6k J/cm时焊接接头的抗拉强度随着机械振动加速度的增加而增大。当焊接热输入为22.8kJ/cm时,机械振动加速度为0和15 m/s2时的焊缝区域的组织都为先共析铁素体+少量珠光体,在晶内还有针状铁素体和极少量的粒状贝氏体组织;当焊接热输入为26.6、31.6kJ/cm时,不同机械振动加速度下焊缝组织主要为先共析铁素体和柱状晶;随着焊接热输入的增加,Q345B钢焊接接头熔合区的组织呈逐渐粗化的趋势。施加机械振动可以一定程度地改善熔合区的组织形态。
The effect of mechanical vibration acceleration on the mechanical properties and microstructure of Q345B steel welded joint under different welding heat input was studied. The results show that under the same mechanical vibration acceleration, the welding heat input of welding joints with descending order of yield strength is 22.8kJ / cm> 26.6kJ / cm> 31.6kJ / cm, To the smallest welding heat input are: 31.6kJ / cm> 26.6kJ / cm> 22.8kJ / cm. The tensile strength of welded joints increases with the increase of mechanical vibration acceleration when the welding heat input is 26.6 and 31.6k J / cm. When the welding heat input is 22.8kJ / cm, the microstructure of the weld zone with mechanical vibration acceleration of 0 and 15 m / s2 is proeutectoid ferrite + a small amount of pearlite, and there is acicular ferrite And a very small amount of granular bainite. When the welding heat input is 26.6, 31.6 kJ / cm, the weld microstructure is mainly pro-eutectoid ferrite and columnar crystal under different mechanical vibration accelerations. With the welding heat input Increasing, Q345B steel welded joint fusion zone of the organization is gradually coarsening trend. Applying mechanical vibration can improve the morphology of the fusion zone to a certain extent.