Cemented carbide tools in high speed cutting, must use water - based processing fluid. However, it was found that cobalt and tungsten carbide in cemented carbide could be leach out by water-based processing liquid. In this paper, the effects of triethanolamine solution, sodium carbonate solution and benzotriazole solution on the leaching of cobalt and tungsten carbide in carbide cutting tools at different temperatures were studied by means of immersion test and sem and eds analysis. The experimental results show that the solution of triethanolamine has the effect of leaching cobalt in cemented carbide cutter, the leaching rate of drilling at room temperature is 17.32%, and the leaching rate of cobalt at 150 degrees is 47 with the increase of temperature. 72%; Sodium carbonate solution has a leaching effect on tungsten carbide cutting tool. 28%. With the increase of temperature, the oxidation dissolution of tungsten carbide intensifies, and the leaching of tungsten element becomes more obvious. At 150 degrees, the leaching rate of tungsten is 45. 59%; Benzotriazole solution has no leaching effect on cobalt in cemented carbide, and has no obvious leaching effect on tungsten in cemented carbide. The leaching rate of tungsten at 150 degrees is 1. 28%.

The additives in cutting fluid can promote the leaching of tungsten carbide in carbide cutting tools. Tungsten carbide leaching not only reduces the tool life, causes the waste of resources, but also causes asthma, pulmonary fibrosis and allergic dermatitis. Aimed at cutting process, carbide cutting tools in the phenomenon that the tungsten carbide leaching screening of some commonly used in water base cutting fluid and organic additives, inorganic additives they are investigated respectively the influence law of cemented carbide tungsten carbide in the leaching, leaching mechanism, and synthesis effective inhibitors prevent oxidation dissolution of cemented carbide tools. The results of immersion test of cemented carbide blade in aqueous solution show that some corrosion pits appear on the surface of the blade after immersion in distilled water. When sodium carbonate solution is added, the alkalinity of aqueous solution decreases and tungsten carbide leaching on blade surface becomes more serious. The above phenomena indicate that tungsten carbide in carbide blades will oxidize to form tungsten trioxide in aqueous solution. When sodium carbonate is added, tungsten trioxide generates its own complex anion tungstate in sodium carbonate solution, which aggravates tungsten leaching due to its high ionization potential and good ability to attract ligands. In order to effectively inhibit the tungsten carbide leaching on the surface of cemented carbide cutting tools, the effects of different additives in cutting fluid on the leaching of tungsten carbide were studied. Triethanolamine oleate is an adsorbent corrosion inhibitor. Hydroxyl group and carboxyl group (polar group) are adsorbed on the surface of the blade. At the same time, a longer carbon chain (non-polar group) separates the blade from the external medium, effectively inhibiting the oxidation dissolution of tungsten. Benzotriazolium is a nitrogen-containing heterocyclic compound. The lone pair of electrons of nitrogen atoms make it have a good electron-absorbing ability. The coordination compound is adsorbed on the blade surface with the empty orbital of cobalt, the binder on the blade surface, and inhibits the oxidation dissolution of tungsten. The best ratio was determined by orthogonal test, and the aqueous solution of borax, triethanolamine oleate and benzotriazole had a good inhibition effect on tungsten carbide leaching. The results of grinding carbide blade and friction test between carbide blade and steel show that the combination of the three can effectively inhibit the leaching of tungsten carbide on the surface of carbide tool. Selecting cutting fluid additive that can effectively inhibit the extraction of tungsten carbide from the surface of carbide cutting tools can not only prolong the tool life, reduce the cost, save resources and protect the environment.

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