Stainless steel screws Inspection Act

About stainless steel screwsfastenerThe test methods are the following four:

      First, the appearance quality requirements

      Stainless steel screws appearance of the test is to test the various aspects of the appearance of the plating layer.

      Second, the screw coating thickness testing

      1, measuring method: The amount has micrometer, calipers, plug and so on.

      2, the magnetic method: magnetic coating thickness measurement is non-destructive measurement of the thickness of the magnetic layer of non-magnetic coatings on magnetic substrates is performed.

      3. Microscopy: Microscopy has called metallographic method, it is etched through a fastener having a micrometer on the microscope eyepiece enlarged, cross-section measurements on the coating thickness.

      4, the time sap flow method

      Timing flow method is used to make the coating dissolved solution streamer on the partial surface coating, the coating was dissolved according to the local time required for completion, to calculate the thickness of the coating. There are topical coatings, anodic dissolution Coulomb law.

      Third, the screw coating adhesion strength test

      Evaluation of coating and substrate metal adhesion in many ways, there are usually several.

      1, friction polishing test;

      2, rasp test method;

      3, scarification;

      4, bending test;

      5, thermal shock test;

      6, the extrusion method.

      Fourth, stainless steelScrewNail coating corrosion test

      Coating corrosion test methods are: the atmosphere insolation test; neutral salt spray test (NSS test); acetic acid salt spray test (ASS test), copper accelerated acetic acid salt spray test (CASS test); and etching cream corrosion test (CORR test) and a solution of drip corrosion test; immersion test, between immersion corrosion test, and so on.