The components of the extruder screw frequently suffer from wear and tear, and the cost of direct replacement is relatively large, and the economy is poor. Today we perform repair welding on the worn part of the extruder screw, and then achieve the purpose of saving production costs, reducing labor intensity, and improving labor productivity.
The extruder screw is made of 38 chromium molybdenum aluminum material, which is nitrided and heat treated after processing. Such a process is now more common. Our extruder screw has a service life of approximately 300,000 meters under this process.
With the increase of orders for magnetic strips, a large number of extruder screws will be used, and the number of worn extruder screws will increase. In the past, the extruder screw has been repaired, and the general carbon steel electrode is selected. The surface hardness is HRC ≥ 40, and the service life is generally 80,000 meters, which cannot extend the service life.
In view of the large wear of the extruder screw due to the hard magnetic powder, and the high processing cost of the screw of the extruder, from the perspective of reducing the cost, it is conceived to select a suitable welding rod and surfacing on the waste screw to extend its service life.
Use high-chromium tungsten carbide welding rods for surfacing welding on the worn parts of the extruder screw. Tungsten carbide has high wear resistance and high temperature resistance. The surface hardness after surfacing is 65, which is suitable for the use environment of the screw and achieves the purpose of prolonging the service life of the screw.
Purchase ф3.2 high chromium tungsten carbide electrode. First put the welding rod in a heat treatment furnace at 100℃～200℃ for heating. The waste screw is heated to about 100°C with oxygen fire, and the abraded part of the extruder screw is surfacing welded with a heated high-chromium tungsten carbide electrode. Spot welding is used when welding, and the surfacing diameter should not be too large. If the welding rod is too large, the welding rod will be wasted, and the manual grinding allowance will be large, resulting in low labor efficiency.
The surfacing diameter should not be too small. If it is too small, there is no effect. After the surfacing is completed, let the extruder screw slowly cool in the air, and then polish it with a hand grinding wheel after cooling. After polishing, use a new short sleeve for testing. If the short sleeve can pass through the modified extruder screw, it is qualified. If it cannot pass, continue polishing. After surfacing welding with a high-chromium tungsten carbide electrode, the hardness HRC of 65 was detected.
Our company specializes in producing parallel and co-rotating modular screw elements, barrels and screws, covering various models from Ø20mm to Ø300mm. After ten years of vigorous development, our company now has a number of advanced CNC machine tools and special processing equipment for screw manufacturing. Now our machining operations have basically realized intelligence and automation.
Advanced processing methods, strong technical force, and sophisticated processing technology ensure that the quality and technical indicators of each production fully meet customer requirements. If interested, please consult.