Overlay welding is a very common repair process. After the chromium carbide wear plate is damaged, it can be repaired by submerged arc welding.
The steel plate repaired by surfacing can not only extend the service life, but also improve the production operation rate, and the effect is very significant.
Before the chromium carbide wear-resistant plate surfacing repair, the surface of the steel plate must be cleaned to remove oil and rust and other debris on the surface of the steel plate. The rest is the treatment of various cracks and trachoma on the steel plate, which are generally carried out by turning.
In order to further confirm the qualification of the steel plate after butt welding repair, flaw detection is needed; then the preheating step is entered, especially when the carbon content in the steel plate is greater than 0.58. Preheating is to prevent cracks and overlay layers in the weld zone during surfacing. Crystal cracks occur in the metal, which is the basis for obtaining high-quality surfacing repair effects.
During the hard facing repair process of chromium carbide wear-resistant plates, the hard facing materials and operating techniques are emphasized. It should be known that the hard facing materials should have high yield strength and section shrinkage at 780 ° C, and the linear expansion coefficient should be small. The change point should also be maintained above 780 ° C. And; for different working positions of chromium carbide wear plates, different overlay materials should be used.
In order to improve the quality of the hard facing layer of chromium carbide wear-resistant plate, the surfacing repair can use low-voltage, low-current, thin-layer multiple surfacing methods. When operating, pay attention to control the center vertex of the steel plate and the position of the welding wire and the inclination of the welding wire angle.
After the completion of the surfacing repair, the heat preservation and slow cooling are performed first, and then the heat treatment is performed in the heating furnace. In addition, an ultrasonic flaw detector is used to inspect the welding defects inside the steel plate to ensure that the quality standards have been reached after the repair of the chromium carbide wear-resistant plate.