It is necessary to have the proper welding materials, welding power supply, welding auxiliary equipment, crown block and electric furnace before starting a zinc alloy die casting plant. Second, make use of the proper welding procedure: 5 methods to overcome defects in electroplating of zinc alloy die castings

1. Mold cleaning and inspection are the first step.
The cleaning and inspection of the mold that will be repaired will serve as the foundation for determining the most appropriate welding repair method. The zinc alloy die casting factory must determine the welding repair process based on the inspection results after cleaning, including the model and quantity of welding materials used, and achieve the repair goal by combining welding materials in the appropriate combination based on the mold conditions.

2. Thoroughly clean the cavity
Several cleaning steps must be completed before welding to ensure that the crack, scaling and fatigue layer are completely removed, as well as that sufficient openness is maintained. In general, an angle of 40-60 ° is required to ensure that the welding rod or welding wire can be deposited properly during the welding process.

3. Pre-weld heating is the third step.
Heating the mold prior to welding is a critical step in completing a successful mold repair. The heating temperature ranges between 800 and 900 degrees Fahrenheit. Time spent per inch of thickness is taken into consideration when calculating and insulating the structure. The total number of hours spent welding in the heating furnace or in the heating flame is determined by the quality of the insulating material used and the calorific value of the heating flame used in the welding.

4. The location of the weldment
The weldment must be simple enough for the welder to operate in the area where it is to be done. Occasionally, the position of the weldment must be adjusted continuously throughout the welding process; however, the center line of the cavity to be welded must be perpendicular to the ground at all times during the welding process. During welding, a short arc must be used to ensure that the welding wall is closely integrated with the welding material, and the welding wall must be visible to the welder. The welding wall must also be within the welder's line of sight.

5. Knocking out the welds after they have been completed
To achieve the best crystal structure of the cladding layer and to prevent the weldment from shrinking along the center line during cooling, it is necessary to knock each weld bead with an air pick or mechanical method after it has been formed.

6. Heat treatment and normalization after welding
In order to prevent the workpiece and cladding from cooling too quickly, the post-weld heating and normalizing temperature is 800-900 ° F, calculated as 1 hour per inch of thickness.

7. The cooling process is slow.
Slow cooling refers to the process by which a weldment is gradually cooled to room temperature in an air-static environment over time. When using slow cooling, the goal is to achieve a balanced microstructure and toughness in order to obtain the best effect possible during the forging process.

8. Stress-relief that is more moderate
Ultimately, the goal is to eliminate the stress generated during welding and achieve the toughness required by the die as well as the hardness required by the cladding layer. The time required for tempering is calculated as 1 hour per inch of thickness.

9. Concluding cooling
Finally, in an air static environment, the weldment is slowly cooled to room temperature as the welding process is completed. Thermal insulation materials can be used to cover the weldment in order to increase the effectiveness of the slow cooling process.

For the zinc alloy die casting factory, repairing the mold is a routine part of the production process. If the mold is properly repaired, mass production can be resumed in order to achieve the desired cost-saving effect.