For these applications, as steel thickness is increased, heavier galvanize coating should be used to insure sufficient galvanic edge protection for the increased cut edge surface area. Galvanized Sheets - Continental Steel & Tube Company. The material categories are: Plate, Structural Shape, Strip and Bar. The corrosion rate of a galvanized coating is generally linear. 3. Cling film comes in at 10-12 microns thick and a typical bacterium is 1-10 microns long. Revised in 2010, the 2-sided, full color chart shows the time to first maintenance of hot-dip galvanized steel in five different atmospheric environments. Your email address will not be published. A minimum of 5 spot readings are obtained for each material category in the specimen area. Table 2 indicates that the galvanizing thickness of Coating Grade 100 is 100 microns or 3.9 mils. in. A typical coating thickness is 45-85 μm but thicker coatings can be produced on structural steelwork by grit blasting the steel prior to galvanizing. of articles coating coating coating mass (all components thickness thickness minimum including castings) minimum minimum g/m2 mm µm µm <8 25 35 250 *8 40 55 390 Notes: 1. For one-side or differential coating, please inquire. This article provides a brief overview of the key points, but users should thoroughly read and understand ASTM A123 when measuring the thickness of hot-dip galvanizing. Prevent product failure by ensuring coating thickness and uniformity of … A minimum of 5 spot readings are obtained in each specimen area. In the bath, the steel product is sent around a submerged roll and reacts with the molten metal to create the bonded coating, and then removed in a vertical direction. Step 1. These variables are represented in the table below. The specimen coating thickness shall be the average of a minimum of 5 readings at widely dispersed points. This article is based on the use of magnetic gages to measure galvanizing thickness according to ASTM-A123, including the number of galvanized articles to be sampled, the number of thickness measurements to be taken, and the acceptance criteria. Multi specimen, single material category. Thinkness. But how does that microscopic coating translate into performance? The corrosion resistance provided by the zinc coating is in direct proportion to the coating's thickness. Silicone which is used to deoxidise steel will affect coating thickness too: the more silicone present, the more reactive the zinc and the greater the thickness of the galvanized coating. Average the readings for each material category/coating grade in the specimens and for the entire sample (average of the averages) to determine compliance. Determining the Required Galvanizing Coating Thickness. For requirements for threaded fasteners refer to AS 1214. Select the sample (number of articles) for testing based on the total number articles in the lot for each specimen type. Jinan Sino Steel Co., Ltd was one large Steel Holding Company, as a window of foreign trade of Chinese Steel industry, our company has been conducting extensive exchanges and friendly co-operations with domestic and overseas companies on the ba In reality, this may not be the case because multiple material categories and coating grades are often present in each specimen. If there are multiple material categories in the specimen, each category is measured separately, and the averages compared for the individual categories. HOT DIP GALVANIZED STEEL, known as ZINCGRIP® Steel, is continuously coated on both sides with a zinc coating. Linkedin, Know your Microns – Galvanized Steel Coating Thickness. For each specimen, identify the different material categories and coating grades present, and obtain dry film thickness readings of each. 2. Before and during use, the accuracy of the instrument should be verified according to ASTM E376, Standard Practice for Measuring Coating Thickness by Magnetic-Field or Eddy Current (Electromagnetic) Testing Methods. Any of the three [3] averages may be one coating grade below the requirement provided the grand average is the coating grade requirement. The 55%Al-Zn coated steel shows mechanical thickness of galvanized coating (BHP Steel, 1994a). The galvanizer and inspector will need drawings to determine the wall thickness, if an open end is not available for measurement. If there are multiple material categories present in each area are averaged to obtain 3 averages per article point,... Than one coating thickness depends on the mass and thickness of up to 80 years the. 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