After pouring,the rough lost wax casting is finished. Then many processes need to be done including removing the shell on the casting,cutting,shot blasting,grinding and repair welding. Among those processes,repair welding used in lost wax casting is very important because it can improve the qualified rate of investment castings. The detailed introduction of repair welding is the following:
1.We have to fix the place,size and the types of the defects. Then get the weld equipment ready.
2. Dig certain areas around the defects. And then,grind or machine the suitable welding grooves.
3. Choose suitable weld materials. Usually the welding material is the same or similar as the castings.
4. Choose the right welding speed and welding types according to the size,depth and types of the defects. The final welding should be raised from the casting surface,then it will be smooth by grinding or machining.