1. black six angle bolt blackening treatment, degreasing must be thorough. Because the black liquor at ambient temperature is acidic and has no oil removal capacity, the oil must be removed from the pretreatment process. There are many ways to remove oil, which are chosen according to their own conditions. After degreasing, it is best to rinse and rinse, and the floating oil on the rinsing tank must be removed in time so as to prevent the workpiece from being polluted again. The way to check the effect of oil removal is to observe a uniform and continuous water film on the surface of the workpiece. If there is a water drop or uneven water film discontinuity, it means that the surface is oily, not clean, should not hesitate to rework.
2. black six angle bolts blackening carefully observe the master of different kinds of blackening film material growth time, namely the formation of black film groove when the uniform. Stay in the air for 1-2 minutes, to the next step, leaching dehydration antirust oil, film density increases, better adhesion, this method is helpful to get the film covered well with the lowest cost.
3. black six angle bolts blackening process after the completion of stay in the air, to quality checks, such as black film, spotted the show, touch off the black, do not force to enter the next process, especially the immersion process, and timely check the reason to be excluded.
4. film black out is generally two cases: first, poor processing of the previous work, two is black time is too long. The judging method is to check whether the black film is exposed or not. The exposed matrix shows that the blackening time is too long and the substrate should be treated again.
5. blackening six angle bolt blackening treatment, keep the degreasing agent and hydrochloric acid concentration of working fluid, especially hydrochloric acid concentration. Is the material base for ensuring the quality of pretreatment.