Various problems arise when welding nm400 wear-resistant steel. Today, I simply sorted out some common problems and solutions, hoping to help everyone.
Surface porosity
Surface pores during welding of nm400 wear-resistant steel are generally caused by unqualified welding materials, unqualified workpiece surface cleaning, incorrect electrode angle during operation, or unsatisfactory construction environment.
How to solve the problems in the welding of nm400 wear-resistant steel plate
Prevention: Use the correct welding material, clean the workpiece before welding, and choose a suitable welding angle.
Remedy: Use an angle grinder or welder chisel to clean up the defect. If the surface shape of the weld after the defect is eliminated cannot meet the standard requirements, repair welding must be carried out again. The position of arc ignition and arc extinguishing must be considered during repair welding. After the repair welding is completed, the weld should be ground and cleaned again to make the transition smooth.
2. Reasons for incomplete welding
The reason for the incomplete weld is generally due to the weak sense of responsibility of the welder or the improper form of the workpiece groove.
Prevention: Select the appropriate workpiece groove.
Remedy: Repair welding must be carried out again. Necessary cleaning should be carried out before repair welding. The arc ignition and arc extinguishing positions must be considered during repair welding. After the repair welding is completed, the weld should be ground and cleaned again to make the transition smooth.
3. Causes of undercut
The cause of the undercut defect is the improper operation of the welder or the excessive current, or the improper angle of the electrode and the welding torch during the welding process, so that the molten base metal is not filled with the weld metal.
Precautionary measures, correct selection of current, electrode (gun) angle and welding speed, and appropriately extend the residence time on both sides of the weld. How to solve the problem in the welding of nm400 wear-resistant steel plate
Remedy: Use an angle grinder or a file to file and grind the undercut defect. For minor undercut defects, it is considered acceptable if the defect is removed and a smooth transition is achieved and the standard requirements are met. For deep undercut defects, repair welding should be carried out after repair welding and grinding.
4. Causes of cracks
Cracks are usually caused by improper selection of the welding process or contamination of the workpiece with oil, water and other contaminants during welding or strong external stresses at the welded joint.
