How can the improved heat treatment process of 3Cr2W8V steel nozzle head be without a small medium frequency induction heating power supply?

The die-casting machine is a special equipment for producing and processing lighter ignition steel wheel cards and other workpieces. The nozzle head is an important part of the 7.5t die-casting machine. The material of the parts is 3Cr2W8V steel, and the hardness after heat treatment is required to be 44-48HRC. During production, it was found that the nozzle head had insufficient hardness or cracks and corrosion defects after heat treatment, and even caused the product to be scrapped.

The inspection found that when the hardness of the nozzle head is low, because the nozzle head and the fixed mold gate sleeve must match well and are in continuous contact, the head will become hairy and its diameter will decrease, resulting in a decrease in the injection flow rate and insufficient material supply to the mold cavity. Sufficient, defects such as incomplete and incomplete die-casting parts are prone to occur; and when cracks appear on the nozzle head, due to the corrosive effect of the zinc material solution on the die-casting parts, the cracks will expand or even penetrate. When the workpiece is pressed, the zinc material will flow from the nozzle head If the extruded part scatters or collapses, the production is very unsafe and production accidents are easy to occur. Strict precautions must be taken.

In view of the above inspection and analysis, after production testing, the following measures for improving the process are proposed: After the workpiece is forged, a small medium-frequency induction heating power supply is used for spheroidizing and annealing, and then is finished. After finishing, a small medium-frequency induction heating power supply is used for quenching and tempering. Fire treatment, followed by liquid nitrocarburizing. Usually 3Cr2W8V steel parts should be tempered 2-3 times. This improved process uses liquid nitrocarburizing instead of the second tempering. After heat treatment, the surface hardness of the workpiece reaches 750-850HV0.1 (equivalent to 62-65HRC), the depth of the compound layer is approximately 0.003-0.010mm, and the depth of the diffusion layer is 0.10-0.18mm.

After adopting the improved process in production, no crack corrosion or insufficient hardness defects were found in the nozzle head, the quality of the workpiece was greatly improved, meeting production needs, and its service life was increased by 2-3 times. If you are still using traditional equipment for quenching and tempering heat treatment, then quickly change to a new small medium frequency induction heating power supply. I believe you will make unexpected discoveries.