怎样防止彩涂镀锌板出现裂纹

唐山天物彩板专注定制彩板16年——鞍山彩涂镀锌板防裂纹_鞍山彩涂镀锌板规格齐全  更多信息请拨打网站上方电话咨询了解

彩涂镀锌板在焊接前易开裂。为什么会这样？因此，在弄清裂缝产生的原因之前，首先要弄清裂缝产生的原因，才能防止事故发生。彩涂镀锌板槽附近的锌层在电弧热的作用下产生氧化（形成氧化锌）和蒸发，并蒸发白色粉尘和蒸汽，很容易在焊缝中产生气孔。

焊接电流越大，锌的蒸发越严重，气孔敏感性越大。钛型和钛钙型焊条焊接时，在中电流范围内不易产生气孔。采用纤维素型和低氢型焊条焊接时，在小电流和大电流下容易产生气孔。另外，电极的角度应控制在30～70之间。

其次， 彩涂镀锌板采用电弧焊焊接时，熔池附近的锌层氧化成氧化锌，在电弧热的作用下蒸发，形成大量烟尘。因此，必须采取良好的通风措施。在相同的焊接规范下，氧化钛电极焊接产生的烟尘量较低，而低氢电极焊接产生的烟尘量较大。

最后，当彩涂镀锌板焊接电流较小时，加热过程中氧化锌的形成不易逸出，导致氧化锌夹渣。氧化锌的熔点为1800℃，大块氧化锌渣对焊缝塑性有非常不利的影响。使用氧化钛电极时，氧化锌分布均匀，对塑性和抗拉强度影响不大。使用纤维素或氢电极时，焊缝中氧化锌含量越来越大，焊缝性能较差。

The color galvanized sheet is prone to crack before welding. Why does this happen? So we need to understand the causes of cracks before we can find out the causes, so as to prevent accidents. The zinc layer near the groove of color-coated galvanized sheet produces oxidation (forming zinc oxide) and evaporation under the action of arc heat, and evaporates white dust and vapor, so it is very easy to cause Blowhole in the weld.

The higher the welding current, the more serious the evaporation of zinc and the greater the pore sensitivity. It is not easy to produce Blowhole in medium current range when welding with Ti-type and Ti-Ca-type electrodes. When using cellulose type and low hydrogen type electrodes to weld, gas holes are easily produced under low current and high current. In addition, the angle of electrode should be controlled in the range of 30 ~70.

Secondly, when the color-coated galvanized sheet is welded by arc welding, the zinc layer near the molten pool oxidizes into zinc oxide and evaporates under the action of arc heat, forming a large amount of smoke and dust. Therefore, good ventilation measures must be taken. Under the same welding specifications, the amount of fume produced by titanium oxide electrode welding is lower, while that produced by low hydrogen electrode welding is larger.

Finally, when the welding current of color-coated galvanized sheet is small, the formation of zinc oxide during heating process is not easy to escape, resulting in zinc oxide slag inclusion. The melting point of ZnO is 1800 C. Bulk ZnO slag has a very adverse effect on weld plasticity. When using titanium oxide electrode, the distribution of zinc oxide is fine and uniform, which has little effect on the plasticity and tensile strength. When using cellulose or hydrogen electrodes, the zinc oxide in the weld is larger and more, and the performance of the weld is poor.