During the automatic surfacing welding of the roller in the roller mill, pre-welding heat treatment is generally not required. However, when the ambient temperature is below 5°C, preheating measures should be considered, with a preheating temperature of 20°C to 40°C being preferable.

During roll press roller surfacing, the preheating temperature should be determined based on the carbon equivalent of the matrix material, and during online welding, the preheating temperature should be below 200°C.

Pre-welding Treatment

1. Wear-resistant Plate Stacking Welding Equipment: Pre-welding Treatment for Hard-faced Stacking Welding Re-manufacturing

1) Prior to welding for worn-out mill roller sleeves or liners, as well as wear-resistant mill disk linings, pre-weld treatment should be conducted. This involves cleaning oil, rust, and other debris from the welding areas of the wear-resistant components, and removing loose cracks on the wear-resistant parts through means such as gas cutting.

Prior to surfacing the extrusion roller for wear failure, pre-welding treatment is required. Remove the incomplete pattern layer, hard surface layer, and fatigue layer on the roller surface using methods such as carbon arc cutting, minimizing the amount removed. During the process, pay attention to the roller surface flatness and the roller body ellipticity. After treatment, maintain the roller body ellipticity ≤ 3mm using an appropriate method. Then, thoroughly remove any slag and carburization layer from the roller surface, clean the roller surface, and dry it after confirming no cracks with a flaw detection.

4.2 Pre-welding treatment for the composite wear-resistant pipe fabrication

1) Prior to surfacing, the casting cores of grinding roller sleeves or grinding roller linings, as well as grinding disk linings, should be mechanically machined to achieve a smooth and shiny surface with metallic luster, free of residual metal oxide layers, and dimensions that meet the surfacing design requirements.

Before surfacing welding, the wear-resistant plate should be cleaned of dust, oil, and other impurities from the base material surface. Sand off surface rust to achieve a smooth and flat base material surface.