Common Cleaning Problems Of Hexagon Socket Head Bolt

  • In order to better use fasteners, regular maintenance is required during use, such as regular cleaning, to improve its efficiency. However, when we clean, we often find some problems. The following China Stud Supplier - weigao will tell you what are the six major problems:

    1. Surface residue

    There is a white residue on the high-strength screw, and the infrared spectrometer is used to analyze and check that the residue is phosphide. No acidic detergent was used for cleaning, and the rinse tank was checked to find that the tank liquid had carbon solubility. The bath should be poured out regularly, and the concentration level of the lye in the rinse tank should be checked frequently.

    1. Unreasonable stacking of fasteners

    After the fastener is tempered, there are signs of discoloration. Soak them in ether. After the ether had evaporated, an oily residue was found. These substances are high in lipids. The results showed that it was contaminated by detergent and quenching oil during rinsing, and melted at the heat treatment temperature, leaving traces of chemical combustion. The surface of these materials is not clean. Infrared spectrometer analysis is a mixture of base oil and ether in quenching oil. The ether may come from the addition of quenching oil. The analysis and inspection of the quenching oil in the mesh belt furnace confirmed that it would stack up unreasonably during heating, and there were traces of slight oxidation in the quenching oil, which were almost negligible. This phenomenon is related to the cleaning process, not the quenching oil. problem.

    1. Alkali combustion

    The high-strength screw has a uniform and flat oil-black outer surface after the heat of quenching. However, there is a visible area of ​​the courseware in the outer circle. In addition, there are some visible areas of light blue or light red. The original bar and wire rod are coated with phosphating film to facilitate cold heading and tapping. They are directly heat treated without rinsing, cooled in quenching oil, cleaned with alkaline cleaning agent, blow-dried (not rinsed), and returned at 550°C. When heating, take out the immersed anti-rust oil from the tempering furnace and find red spots on the threads.

    It was detected that the red area on the screw was caused by alkali burning. Alkaline cleaners containing chloride substances and calcium compounds burn steel fasteners during heat treatment, leaving marks on the surface.
    Hexagon Socket Head Bolt cannot remove the surface alkaline substances in the quenching oil, thus burning the surface in the high-temperature austenite state, and aggravating the damage in the next step of tempering. It is recommended to clean and rinse thoroughly before heat treatment to thoroughly remove alkaline residues that can cause fastener burns.