check the quality of blade welding?

In order to ensure the welding quality, the blade after welding should be carefully checked to find out the cause of the defect and improve it. Before inspection, the blade should be sandblasted or lightly ground to remove the solder and impurities adhering to the blade surface, and cleaned with kerosene. The inspection items and requirements are as follows:

1. check the strength of the weld: Use a green silicon carbide grinding wheel to grind the back of a blade and check the thickness of the solder layer. The thickness is required to be below 0.15mm. There shall be no air holes and insufficient solder at the bottom surface of the tool tip support, and the weld not filled with solder shall not be more than one tenth of the total length of the weld. If there are pores, the blade will fall off when cutting.

2. check the position of the blade in the knife groove: if the blade is misaligned and sagging exceeds the technical conditions, it should be re-welded.

3. check the welding strength: use a wooden hammer or a copper hammer to hit the blade with medium force, or use an I hammer to hit the blade with strong force. At this time, the blade is qualified if it does not fall off from the blade body. To check the welding strength of the blade, it is not necessary to check one by one, but also to use spot checks.

4. check the flatness of the blade: if there are obvious pits on the blade, it means that the blade is overheated and deformed, and a new blade should be burned and re-welded.

5. check the crack: after the blade is cleaned by kerosene, if the blade has a crack, the kerosene penetrates into the crack and the black line appears, which can be observed with the naked eye. It can also be observed with a magnifying glass of 10-40 times.

check the blade crack, color flaw detection method can also be used: use 65% kerosene, 30% transformer oil and 5% turpentine solution, slightly add some Sudan red. The turning tool blade part is placed in the solution for 10-15 minutes, then washed with clear water, coated with a layer of clay (kaolin), and observed its surface after drying. If there is a crack on the blade, the color of the solution will be exposed on the clay and can be seen with naked eyes. The cracked blade cannot be used and needs to be re-welded.

In addition to the several commonly used car 7J welding methods described above, there are also methods such as oil protection, electric furnace, forging furnace and furnace brazing with reducing gas, which will not be described in detail here.