Q235薄平板TIG堆焊失稳变形演变研究

Research on instability deformation evolution of Q235 thin bead-on-plate TIG welding

针对Q235薄平板TIG焊接产生的失稳变形复杂且难以控制的问题,研究了薄平板失稳的判定方法,阐明了薄平板在整个焊接及冷却过程中的失稳变形状态,分析了薄平板焊接失稳演变机理。研究表明,Q235薄平板在TIG堆焊及冷却过程中,失稳变形状态由拱形逐渐向反马鞍形过渡;失稳变形由焊缝周边的压应力引起并且在焊接加热过程中发生;薄平板位移式的内应力加载方式使得失稳变形过程存在于两个变形拐点之间。

In view of the complex and difficult to control the instability deformation caused by the Q235 thin plate TIG welding, this paper studies the judgment method of the thin plate instability, clarifies the instability deformation state of the thin plate in the whole welding and cooling process, and analyzes the law of instability evolution of thin plate welding.Research shows that during the TIG surfacing and cooling process of the Q235 thin plate, the instability deformation state gradually changes from the arch to the reverse saddle shape.The instability deformation is generated by the compressive stress around the weld and occurs during the welding heating process. The displacement-type internal stress loading method the of the thin plate makes the instability deformation process exist between the two deformation inflection points.