In order to ensure the quality of welding, a careful inspection should be carried out to find out the cause of defects. Before the inspection, the tool should be sandblasted or gently ground to adhere to the solder and impurities on the blade surface, and clean with kerosene.

Check items and requirements.

Check weld strength

After the green silicon carbide grinding wheel is used to grind the back of the cutter, check the thickness of the solder layer, and the thickness is below 0.15mm. No holes and solder defects can be found at the base of the blade, and the welding seam should not be more than 10% of the total length of the weld. If there is a hole, the blade will fall off when cutting.

Check the position of the blade in the knife slot.

If the blade is misaligned and sagging exceeds the technical conditions, rewelding shall be performed.

Check welding strength

Use a wooden hammer or a copper hammer to hit the blade with medium strength or with a hammer with a strong stroke. The blade is not removed from the knife slot to be qualified. Check the welding strength of cemented carbide welding blade, not necessarily each inspection, also use spot check method.

Check the blade flatness

If there are obvious pits on the blade, the blade should be overheated and deformed, and the welding blade should be fired.

Check the crack

When the blade is cleaned by kerosene, if the blade is cracked, the kerosene seeps into the crack and the black line is visible to the naked eye. It can also be observed with a magnifying glass of 10-40 times.

Check the blade crack, and also use color flaw detection: 65% of kerosene, 30% of transformer oil and 5% turpentine solution, slightly more Sudan red. Put tool blade part in 10 to 15 minutes in the solution, then use clean water, coated with a layer of clay (kaolin), the surface was observed after baking thousand, if there is crack on the cemented carbide welding blade, then the color of the solution was revealed on clay, with the naked eye can see. The cracked blade cannot be used and needs to be resoldered.

In addition to the several commonly used car 7J welding methods mentioned above, there are methods such as oil protection, electric furnace, forge furnace and brazing furnace with reducing gas.

Related link: http://www.wococarbide.com/

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Wire drawing die of the scope of application is very extensive, mainly for the drawing bar, wire rod, wire, pipe and other linear difficult processing object, steel, copper, tungsten, molybdenum and other metal and alloy material of drawing processing. As the material that can use tungsten carbide wire drawing die, must have enough strength and wear resistance. The molds of tungsten carbide wire drawing dies are basically WC-Co cemented carbide. WC-Co carbide is composed of very hard elements (tungsten carbide) sandwiched between very soft matrix (cobalt) layers. The most important element in cemented carbide is tungsten carbide. There is only a small amount of the matrix metal film, filled with the space of carbide grains. Since the thermal expansion properties of carbide and cobalt are different, when the matrix metal film is combined with hard particles, they are subjected to severe plastic constraints. This will increase the strength of the base metal and lead to embrittlement of the matrix metal. This actually determines the performance of the cemented carbide. At high temperature, tungsten carbide can still guarantee its hardness. When the temperature reaches 600 degrees, the hardness of cemented carbide can be the same as the hardness of high speed steel at room temperature. Hard metal has higher compressive strength than any kind of artificial material, and it also has high elasticity and rigidity modulus. Other properties of cemented carbide include thermal conductivity better than most steel and low friction coefficient. These characteristics are very important for the fabrication and processing of metal pipes.

The quality of tungsten carbide in tungsten carbide wire drawing dies plays an important role in the service life of wire drawing die. The design and manufacture of tungsten carbide wire drawing dies, if the service life is long, the maintenance is small, and the speed of drawing is improved, the following three problems must be solved:

1. The inlet cone and working cone are lengthened to establish a good lubrication pressure, while the lubricating cone Angle should be shortened appropriately.

2. The diameter belt must be straight, and its height should be reasonable.

3, work cone Angle and sizing belt junction should not have transition Angle, at least to minimize, typically less than 0.5 degree.

The tungsten carbide wire drawing mould is of high hardness, and the quality of the pipe is high and the surface roughness is low. At the same time, the wear resistance of tungsten carbide wire drawing die is good, the service life of die is long. The machining precision, durability and wear resistance of the tungsten carbide wire drawing die are better than that of ordinary pipe drawing dies.

Work drawing die is towards high strength, high hardness, high wear resistance, conforms to the requirements of the new technology and material emerge in endlessly, work drawing die greatly improve wear resistance, wear and damage time delay, obviously increasing life of drawing die, machining accuracy has improved. The application scope of drawing processing is gradually expanding, from coarse to fine specifications of pipes.

The physical and chemical properties of wire drawing die must meet the requirements of high hardness, impact resistance, wear resistance and low friction coefficient. In mass production, long life die materials should be selected, such as tungsten carbide, high strength and toughness, high wear-resistant mould steel (such as YG15, YG20). tungsten carbide has good polishing, low energy consumption, wear-resisting, high temperature resistance, good corrosion resistance, and its recyclable and other excellent properties, making it an important material for drawing mould.

Related link: http://www.wococarbide.com/Transaction/en_information.html

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