When we discuss seamless steel pipe, Seamless steel pipe is with a wide range of applications in our construction industry. in general, Galvanized seamless tube is the hot dip galvanized and electro-galvanized two categories.
The first to introduce hot-dip galvanizing, including wet, dry the, lead, zinc, oxidation-reduction method, etc., the process is very complex, the need for technical maturity to complete. Steel Pipe acid leaching after cleaning, the specific method used to activate the surface of the tube improve the quality of zinc, is not the same, hot dip galvanized main difference.
I do not know understand if understand the electro-galvanized zinc coating surface and compared to a very smooth and dense, homogeneous; the characteristics of the electro-galvanized with good corrosion resistance and mechanical properties; Production is now mainly used in dry and oxidation-reduction method. Coating on one side, the internal and external surfaces of the thickness of the coating on different double-sided smooth coating, and thin-walled tube galvanized to complete this method. Zinc consumption 60% to 75% lower than the hot-dip galvanizing. Electro-galvanized in the operation of technical and general than there is a certain complexity, which requires high technology and conditions in order to complete.
Galvanized steel hardness
Galvanized steel pipe in terms of hardness test is a Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, micro-hardness and high-temperature hardness, etc., which can be divided into a variety, most of the manufacturers or using a Buchner,Rockwell, Vickers hardness of these three methods.
Brinell hardness measurement principle is the test force F (N) with a certain size, the diameter D (mm) of hardened steel balls or carbide ball pressed into the surface of the metal under test, to maintain a predetermined time after the drop test force, the the indentation average diameter d (mm) measured with a reading microscope, and then the equation Brinell hardness HB value, or the value d from the prepared Brinell hardness table to detect HB Brinell hardness measurement method is suitable for cast iron, non-alloy, annealing and quenching and tempering steel, the determination should not be too hard, too small, too thin and the surface does not allow the larger indentation specimen or workpiece.
Rockwell hardness test when the sample is too small or Brinell hardness (HB) is greater than 450, to switch to a Rockwell hardness measurement. The test method is an apex angle of 120 degrees with a diamond cone or the diameter 1.59mm/3.18mm the ball, pressed into the surface of the material under a certain load, the hardness of the material by the indentation depth obtained.
The Vickers hardness means a standard of the hardness of the material. Vickers hardness there is a small negative Vickers hardness test load 1.961 <49.03N, it applies to a thinner workpiece, the tool surface or coating hardness measurement; micro-Vickers hardness test load <1.961N applicable to the metal foil, , of the ultra-thin surface layer hardness measurement.
Post time: Sep-26-2019