| 摘要 |
<p>Seam backing element for single-sided butt welding of metal parts is comprised of a mixt. of a preponderant amt. of quartz sand, together with welding powder (I) and water glass (II) as binder, whereby the amt. of (II) the amt. of (I). The compsn. is hardened by exposure to CO2 to form a solid material conforming in shape to the welded joint. The backing compsn. is hardened e.g. in an extruded profile, which is attached to the back of the joint between the parts to be welded. Welding is then carried out from the other side, during which the backing element produces no gas, prevents running of the weld metal through the air gap between the parts, and reflects heat back into the joint so that hair crack formation in the welded joint is precluded. Use of the backing elements obviates the need to finish the weld from the back of the joint, and thus speeds up and cheapens the welding process.</p> |
