Wrong Cleaning Method For Square Bolts » Discussions


Wrong Cleaning Method For Square Bolts

  • Leader
    March 8, 2020
    Long-term use will inevitably absorb a large amount of dust and rust on it, so cleaning is very important, but do you know what will happen if the [u]Square Bolt[/u] is not cleaned properly?
    1. Pollution during rinsing
    After quenching, the fastener was cleaned with silicate cleaning agent, then rinsed, and solid substance appeared on the surface. The substance was analyzed by infrared spectrometer, which proved to be inorganic silicate and iron oxide. This is due to incomplete rinsing and silicate residue on the fastener surface.
    1. Surface Residue
    There is white residue on the high-strength screw, which was analyzed by infrared spectrometer and proved to be phosphide. No acid cleaning agent was used for cleaning, and the rinsing tank was checked to find that the tank liquid has high carbon solubility. The tank liquid should be drained regularly, and the concentration level of alkali liquor in the rinsing tank should be regularly detected.
    1. Excessive corrosion
    Some black stripes are often seen in high-strength fasteners. It is also seen in experiments that fasteners before heat treatment have been rinsed with inorganic and organic cleaning agents. After quenching, black stripes are still found. Even after careful cleaning before heat treatment, stripes will be left after heat treatment. The residual pollutants on the surface were analyzed by infrared spectrometer, and high concentrations of sulfur and calcium were found. With a small amount of acetic acid isopropyl alcohol, fold a small piece of test filter paper at the black spot and leave the black spot on the filter paper. The filter paper was analyzed by infrared spectrometer, which confirmed that calcium, sulfur, iron, manganese and chromium were the main elements. The above three points are the results of incorrect cleaning methods of square bolts summarized for everyone. It can be seen that we need to clean regularly and the accuracy of cleaning is usually very important, so as to prolong the service life of [u]DIN 603[/u] bolts and ensure that they will not be eroded.