How to Check the Quality of Welding of Inlaid Steel Blades
Publish Time: 2021-01-15 Origin: Site
In order to ensure the welding quality of the steel inserts, the welded blades should be carefully inspected to find out the causes of defects and improve them. Before the inspection, the steel insert 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:
Check the weld strength. Grind the back of a turning tool with a green silicon carbide wheel and check the thickness of the solder layer. The thickness is required to be below 0.15 mm. There should be no pores and insufficient solder on the bottom surface of the tungsten steel tip support. The weld that is not filled with solder shall not exceed 10% of the total length of the weld. If there are air holes, the blade will fall off during cutting.
Check the position of the steel knife in the slot. If the steel blades are misaligned and sag beyond the technical requirements, re-welding should be performed.
Check the welding strength. Strike the blade with a wooden hammer or a copper hammer with medium force, or use a hammer to strike the knife shaft with a strong force. At this time, the steel-inlaid blade does not fall off from the slot. To check the welding strength of the blades, it is not necessary to check them one by one, and spot checks are also used.
Check the flatness of the steel knife. If there are obvious pits on the insert steel blade, it means that the blade is overheated and deformed, and the new blade should be burned and re-welded.
Check for cracks. After the blade is cleaned with kerosene, if the blade has cracks, the kerosene will penetrate into the cracks and black lines will appear, which can be observed with the naked eye. It can also be observed with a magnifying glass of 10-40 times. To check the cracks of the steel inserts, color flaw detection can also be used. Use a solution of 65% kerosene, 30% transformer oil, and 5% turpentine, with a little Sudan red. Put the turning tool blade part in the solution for 10-15 minutes, then wash it with clean water, and apply a layer of white clay (kaolin). Observe the surface after drying. If there are cracks on the blade, the color of the solution will be revealed on the white soil and can be seen with the naked eye. Cracked blades cannot be used and need to be re-welded.