喷瓷管道焊接接头的自熔覆防护

Protection of welded joints of sprayed porcelain pipe by self-deposition of enamel coating

通过分析焊接对喷瓷管道焊接接头处瓷层的影响,提出了用自熔覆法对焊接接头进行防护。试验结果表明,在合适的电流下采用TIG焊打底能够使焊口附近的瓷层重熔并向焊缝流布、熔覆,在焊缝区形成保护层,起到自熔覆防护作用;焊前管端预涂釉浆能有效增加焊后接头区自熔覆瓷层的厚度,提高瓷层的防护效果;焊后采用火焰加热对接头区进行重熔处理,可以消除瓷层中气泡、裂纹等缺陷。采用焊前管端预涂釉浆、TIG焊打底、焊条电弧焊填充、焊后接头区瓷层重熔处理等配套措施能够有效解决喷瓷管道焊接接头的防护问题,焊后不用进行内补口。

The effect of welding on the enamel of the welded joint of porcelain pipe was studied and a new self-deposition protection method was put forward to protect the welded joints of porcelain pipe. The results show that the enamel near the weld can remelt and flow to the weld and cover the weld metal when tungsten inert-gas (TIG) welding is used to backing weld with proper current. Pre-brushing the enamel near the end of pipe before welding can add the thickness of the self-deposition enamel and improve the protection effect. Using flame to remelt the enamel on the welded joints after welding and cooling slowly can re-intenerate the enamel and remove the cracks and air bubbles in the enamel. Using the methods of brushing enamel before welding, backing welding by TIG, filling by shield metal arc welding and remelting enamel on the welded joints by flame can effectively protect the welded joints of porcelain pipe without internal repairing after welding.