第1个回答 2021-12-30
埋弧焊焊接过程中可能出现的主要缺陷，除了熔透不足、烧穿、成形不良以外，还有气孔、裂纹和夹渣等，本文主要介绍气孔和夹渣两种缺陷的产生原因及预防措施。
The main defects that may appear in the process of submerged arc welding are not only insufficient penetration, burn through and poor forming, but also porosity, crack and slag inclusion. This paper mainly introduces the causes and preventive measures of porosity and slag inclusion.
一、气孔
一、Stomata
主要原因及预防措施如下：
The main causes and preventive measures are as follows:
1.焊剂吸潮或焊剂中的水分、污垢及氧化铁屑会造成气孔，这在回收焊剂中更为突出，水分可通过烘干消除，烘干温度和弯头应由焊剂生产厂家规定，正确储存和保存可以预防焊剂吸水，采用真空式焊剂回收器有效分离焊剂与尘土，减少出现气孔的可能性。
1.Moisture absorption of flux or moisture, dirt and iron oxide chips in flux will cause pores, which is more prominent in the recovery of flux. Moisture can be eliminated by drying. The drying temperature and elbow shall be specified by the flux manufacturer. Correct storage and preservation can prevent the flux from absorbing water. Vacuum flux recycler is used to effectively separate flux and dust and reduce the possibility of pores.
2.焊剂覆盖不充分会因电弧外露，卷入空气而造成气孔，焊接小直径环缝，应采取适当措施防止焊剂散落。
2.Insufficient flux coverage will cause air holes due to arc exposure and air entrainment. Appropriate measures shall be taken to prevent flux from scattering when welding small-diameter circumferential welds.
3.熔渣粘度过大，溶入高温液态金属中的气体以气泡形式溢出，熔渣粘度大，气泡不能通过熔渣，堵塞在焊缝表面，形成气孔，可以通过调整熔剂化学成分和改变熔渣的粘度来解决。
3.The viscosity of molten slag is too high, and the gas dissolved in high-temperature liquid metal overflows in the form of bubbles. The viscosity of molten slag is high. Bubbles cannot pass through the molten slag and block the weld surface to form pores. It can be solved by adjusting the chemical composition of flux and changing the viscosity of molten slag.
4.焊接时会发生电弧磁偏吹现象，在直流焊接中，电弧磁偏吹会在焊缝中造成气孔，磁偏吹受多种因素影响，如工件上焊接电缆的连接位置，连接处接触不良，接头部分焊接电缆会产生二次磁场，在同一焊缝的不同部位，磁偏吹的方向不同。
4.Arc magnetic bias blowing will occur during welding. In DC welding, arc magnetic bias blowing will cause pores in the weld. Magnetic bias blowing is affected by many factors, such as the connection position of welding cable on the workpiece, poor contact at the connection, and the welding cable at the joint will produce secondary magnetic field. In different parts of the same weld, the direction of magnetic bias blowing is different.
在靠近端部的一段焊缝上，经常发生磁偏吹，因此在这一段焊缝上有更多的气孔，要使用交流电源，工件上焊接电缆的连接位置要远离焊缝终端，避免产生二次磁场。
Magnetic bias blow often occurs on a section of weld near the end, so there are more pores on this section of weld, AC power supply shall be used, and the connection position of welding cable on the workpiece shall be far away from the weld terminal to avoid secondary magnetic field.
5.被污染的工件焊接坡口及附近的铁锈、油污或其他污物会在焊接过程中产生大量气体，促使气孔的形成，应在焊接前清除。
5.Rust, oil stain or other dirt in the welding groove of contaminated workpiece and nearby will produce a large amount of gas during welding and promote the formation of pores, which shall be removed before welding.
二、夹渣
二、Slag inclusion
夹渣与焊剂的脱渣性能有关，还与工件的装配和焊接工艺有关，对接焊缝装配不良时，焊缝底部容易产生夹渣，平而略凸的焊缝比深凹或咬边的焊缝更容易脱渣。
Slag inclusion is related to the deslagging performance of the flux, as well as the assembly and welding process of the workpiece. When the butt weld is poorly assembled, slag inclusion is easy to occur at the bottom of the weld, and the flat and slightly convex weld is easier to deslag than the deep concave or undercut weld.
双道焊的第一道焊缝，与坡口上缘熔合时容易脱渣，焊接第二道焊缝时容易产生夹渣，焊接深坡口时，小焊道组成的焊缝，不容易产生夹渣，大焊道组成的焊缝，产生夹渣可能性大。
The first weld of double pass welding is easy to deslag when fused with the upper edge of the groove, and slag inclusion is easy to occur when welding the second weld. When welding deep groove, slag inclusion is not easy to occur in the weld composed of small weld bead, and slag inclusion is likely to occur in the weld composed of large weld bead.
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