Welding Repair Process Of High Chromium Alloy Casting Lining Plate
Feb 05, 2025| Repair Welding Process
In addition, the welding repair process for high chromium alloy casting liners is particularly important, which includes the following specific three steps: pre weld, during weld, and post weld
Preparation before welding
1. You can choose welding materials with similar composition to high chromium cast iron, such as E309-15 welding rods, whose chemical composition can meet the welding repair needs of high chromium cast iron, effectively ensuring the strength and corrosion resistance of the weld seam.
2. It is recommended that you prepare a DC welding machine to ensure stable output current and meet the welding process requirements. Equipped with tools such as angle grinder and wire brush for cleaning the welding area.
3. Defect cleaning: Use an angle grinder to polish the defect area to be welded, removing impurities such as oil stains, rust, and oxide scale on the surface until a metallic luster is exposed.
welding process
1. Preheating treatment: In order to prevent cracking during welding, the lining plate needs to be preheated before welding. Heat the entire or partial lining plate to 200 ℃ -300 ℃. For specific recommendations, you can use oxygen acetylene flame heating or electric furnace heating methods. For small lining plates, you can evenly heat the area around the welding area within a range of 100mm to 150mm, monitor the temperature in real time with a thermometer, and maintain it for 5-10 minutes after reaching the preheating temperature. This is more conducive to welding and ensuring product characteristics.
2. Welding parameter setting: We need to adjust the welding current according to the specific electrode diameter and base metal thickness. If you want to use a welding rod with a diameter of 3.2mm, please control the welding current between 100-120A. If the DC reverse connection method is to be used, please ensure that the arc burns stably.
3. Welding operation: Using short arcs for rapid welding is the most effective method. The angle between the welding rod and the surface of the workpiece should be maintained at 70 ° -80 °, and the thickness of each weld seam should be controlled at 3-4mm. After each layer is welded, the slag on the surface of the weld seam should be cleaned with a wire brush. And check for defects such as pores and slag inclusions.
Post weld treatment
1. Slow cooling treatment: After welding repair is completed, you can cover the weld seam with asbestos cloth or other insulation materials. The purpose of doing this is to cool it slowly and prevent cracks from occurring due to rapid cooling. Allow the liner to cool to room temperature in a natural environment, but the entire cooling process may take a long time.
2. Grinding and trimming: After the final cooling, an angle grinder should be used to polish the welded area to make its surface flat and level with the surrounding base material, so as to ensure that the lining plate can be installed and used normally in the equipment.