First, sample The performance test of hot-dip galvanized strip is an important production link to improve the product quality and reduce the production cost.
In order to improve the performance test, the first sampling should be reasonable. That is, the number of samples to be less, the sampling position to be representative. The hot-dip galvanized steel strip, which is rolled by continuous casting slab, is not limited in its sampling position and one is a cold rolled coil as a test unit. The hot-dip galvanized steel strip rolled by the initial billet shall be used as a test unit for each ingot to be sampled at the head, center or tail according to the special requirements of the steel and inspection, The According to experience, the sampling position of the sedated steel is specified in the middle of the ingot, ie 50% from the head of the strip, while the boiled steel is sampled at the most segregated part, 25% from the head of the ingot.
And, galvanized defects are not allowed on the specimen. If the specimen surface zinc scar, zinc particles, air knife streaks, exposed steel and other defects will affect the test results. In the hot-dip galvanizing line, in the sub-volume cut a length of not less than 500 mm and strip the same width of the steel plate, and then in the laboratory and then made of various samples, the performance test.
Second, the mechanical properties of the test Hot-dip galvanized steel strip mechanical properties with a variety of test methods, such as: tensile test, deep drawing test, stratification test, hardness test, metallographic test and bending test.
Third, hot dip galvanizing layer adhesion test The main task of hot-dip galvanizing steel is to lay a firm layer of zinc on the steel plate. Therefore, it is of great significance to examine the adhesion of the coating. Inspection, to assess the toughness of the coating and coating adhesion of two indicators. The former is judged by the crack of the zinc layer; the latter is judged by the loss of the zinc layer. According to the thickness of galvanized sheet were used folding test, ball punch test and bending test. The same time as
Fourth, the determination of zinc weight The thickness of the galvanized layer on the surface of the galvanized sheet determines its service life. Therefore, according to different purposes of use, should choose a different thickness of galvanized layer. In order to effectively control the galvanized layer in the production, it is necessary to accurately and quickly determine the thickness of the galvanized layer.
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