四、关于对称的X型坡口从理论上分析,对称的X型坡口具有角变形小和根部应力集中系数小的优点,但在实际生产中往往难以实现。对称的X型坡口,在先焊侧焊后,后焊侧在施焊前,为了确保焊缝质量,根部一般要采取风铲或碳弧气刨的方法清焊根,然后再进行焊接。这样,对称的X型坡口经清根后便不对称了。但即使不清根,先焊侧和后焊侧焊接工艺规范参数完全相同,由于先焊侧产生变形大并对后焊侧起到了增加刚度 Fourth, on the symmetry of the X-groove From the theoretical analysis, the symmetrical X-groove with a small angular deformation and root stress concentration coefficient advantages, but in the actual production is often difficult to achieve. Symmetric X groove, in the first welding side welding, welding side in the welding before, in order to ensure the quality of the weld, the root usually to take the wind shovel or carbon arc gouging methods soldering root, and then welding. In this way, the symmetrical X-groove is not symmetrical after root clearance. However, even if the roots are unclear, the welding parameters of the first welding side and the second welding side are exactly the same. Since the deformation of the first welding side is large and the rigidity of the rear welding side is increased