坡口加工质量的好坏,对焊接质量的影响甚大。它直接关系到焊缝成形及根部熔透情况。对于厚板,如果坡口角度不当,还会出现裂纹。为此,开好坡口至关重要。机械加工开坡口的方法,效率低、成本高。我们采用火焰切割加工13毫米以上厚板的坡口时,钝边尺寸不易保证。例如,焊接H型钢时,坡口要求如图1所示。如果按常规方法从上往下切,由于高压氧风线的漂移,钝边常有烧塌现象,使3~(+1)的尺寸很难保证。而且由于坡口角度大(60°±2°),火焰热量不够集中,虽经放慢切割速度和增加预热火焰的能率,坡 Groove processing quality is good or bad, a great impact on the quality of welding. It is directly related to weld formation and root penetration. For slabs, cracks may appear if the bevel angle is not correct. For this reason, it is crucial to make good bets. Machining the groove method, low efficiency, high cost. We use flame cutting processing more than 13 mm thick bevel, blunt edge size is not easy to guarantee. For example, when welding H-beams, the bevel requirements are shown in Figure 1. If according to the conventional method from top to bottom cut, due to the drift of the hyperbaric oxygen wind line, the blunt edge often has the phenomenon of burning down, so that the size of 3 to (+1) is difficult to guarantee. Moreover, due to the large bevel angle (60 ° ± 2 °), the flame heat is not concentrated enough. Although the cutting speed is slowed and the rate of preheating the flame is increased,