Why is there a crack on the surface of AR400 wear steel sheet

The quality of AR400 wear steel sheet depends on related technology to ensure. The most direct way to judge is to judge from the appearance, the more common is the cracks on the surface of AR400 wear steel sheet. This is a common phenomenon that everyone can see in the factory's warehouse and workshop. As a common crack problem, we should figure out the principle and then deal with it.

The production process of AR400 wear steel sheet adopts metallurgical surfacing welding. The welding current is usually 350-500A. When the temperature of the welding arc reaches 1000-1500℃, the instantaneous high temperature causes the welding wire and the sample plate to reach the melting point to form a molten pool, and the gold powder is added to the pool to melt and form a covering layer. The motherboard generally uses ordinary Q235 low-carbon steel, and the wear-resistant layer is high-carbon and high-chromium. Therefore, during the welding process, the temperature difference of each part of the main board is very large, resulting in extremely uneven expansion, contraction, and deformation. In the cooling process after thermal deformation, in order to release the welding stress in the covering layer composite steel plate, many cracks of different sizes will be generated in the direction of the covering layer surface perpendicular to the weld. This kind of crack is the result of stress release and does not affect the use.