1、 Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products AASHTO Designation: M 111M/M 111-15 ASTM Designation: A123/A123M-13 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-4h M 111
2、M/M 111-1 AASHTO Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products AASHTO Designation: M 111M/M 111-15 ASTM Designation: A123/A123M-13 1. SCOPE 1.1. This specification covers the requirements for zinc coating (galvanizing) by the hot-dip process on iron and ste
3、el products made from rolled, pressed and forged shapes, castings, plates, bars, and strips. 1.2. This specification covers both unfabricated products and fabricated products, for example, assembled steel products, structural steel fabrications, large tubes already bent or welded before galvanizing,
4、 and wire work fabricated from uncoated steel wire. This specification also covers steel forgings and iron castings incorporated into pieces fabricated before galvanizing or which are too large to be centrifuged (or otherwise handled to remove excess galvanizing bath metal). Note 1This specification
5、 covers those products previously addressed in M 111-80, ASTM A123-78, and ASTM A386-78. 1.3. This specification does not apply to wire, pipe, tube, or steel sheet that is galvanized on specialized or continuous lines, or to steel less than 0.76 mm 22 gauge (0.0299 in.) thick. 1.4. The galvanizing o
6、f hardware items that are to be centrifuged or otherwise handled to remove excess zinc (such as bolts and similar threaded fasteners; castings; and rolled, pressed, and forged items) shall be in accordance with M 232M/M 232. 1.5. Fabricated reinforcing steel bar assemblies are covered by the present
7、 specification. The galvanizing of separate reinforcing steel bars shall be in accordance with ASTM A767/A767M. 1.6. This specification is applicable to orders in either SI units (as M 111M) or inch-pound units (as M 111). SI units and inch-pound units are not necessarily exact equivalents. Within t
8、he text of this specification and where appropriate, inch-pound units are shown in brackets. Each system shall be used independently of the other without combining values in any way. In the case of orders in SI units, all testing and inspection shall be done using the metric equivalent of the test o
9、r inspection method as appropriate. In the case of orders in SI units, such shall be stated to the galvanizer when the order is placed. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 232M/M 232, Zinc Coating (Hot-Dip) on Iron and Steel Hardware T 65M/T 65, Mass Weight of Coating on Iron and Steel
10、Articles with Zinc or Zinc-Alloy Coatings 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4h M 111M/M 111-2 AASHTO 2.2. ASTM Standards: A47/A47M, Standard Specification for Ferritic Malleable Iron Cas
11、tings A143/A143M, Standard Practice for Safeguarding Against Embrittlement of Hot-Dip Galvanized Structural Steel Products and Procedure for Detecting Embrittlement A384/A384M, Standard Practice for Safeguarding Against Warpage and Distortion During Hot-Dip Galvanizing of Steel Assemblies A385/A385M
12、, Standard Practice for Providing High-Quality Zinc Coatings (Hot-Dip) A767/A767M, Standard Specification for Zinc-Coated (Galvanized) Steel Bars for Concrete Reinforcement A780/A780M, Standard Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized Coatings A902, Standard Terminolog
13、y Relating to Metallic Coated Steel Products B6, Standard Specification for Zinc B487, Standard Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross Section B602, Standard Test Method for Attribute Sampling of Metallic and Inorganic Coatings B960, St
14、andard Specification for Prime Western Grade-Recycled (PWG-R) Zinc E376, Standard Practice for Measuring Coating Thickness by Magnetic-Field or Eddy-Current (Electromagnetic) Testing Methods 3. TERMINOLOGY 3.1. Definitions: 3.1.1. The following terms and definitions are specific to this specificatio
15、n. ASTM A902 contains other terms and definitions relating to metallic-coated steel products. 3.2. Definitions of Terms Specific to This Standard: 3.2.1. average coating thickness, nthe average of three specimen coating thicknesses. 3.2.2. black, adjdenotes the condition of not galvanized or otherwi
16、se coated. For purposes of this specification, the word “black” does not refer to the color or condition of surface, or to a surface deposit or contamination. 3.2.3. coating thickness grade, nthe numerical value from Table 1 at the intersection of a material category and a thickness range. Table 1Mi
17、nimum Average Coating Thickness Grade by Product Category Product Category All Specimens Tested, Steel Thickness Range (Measured), in. mm 3/16to 4.8 to 100 000 mm2160 in.2YesSubdivide Each TestArticle into ThreeSpecimensOne Specimenper Test ArticleTest Each Specimenfor Compliance withSection 6.1YesE
18、ach SpecimenAvg. Complieswith Section 6.1NoNoLot Fails forThicknessLot Passesfor ThicknessYesAvg. of AllSpecimenComplies withSection 6.1 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4h M 111M/M 111
19、-8 AASHTO 6.1.2. For articles with surface area equal to or less than 100 000 mm2160 in.2 (single-specimen articles), the average of all test articles in the sample must meet the appropriate minimum average coating thickness grade requirements of Table 1, and for each test article, its specimen coat
20、ing thickness shall be not less than one coating grade below that required in Table 1. 6.1.3. No individual measurement, or cluster of measurements at the same general location, on a test specimen shall be cause for rejection under the coating thickness requirements of this specification provided th
21、at when those measurements are averaged with the other dispersed measurements to determine the specimen coating thickness grade for that specimen, the requirements of Sections 6.1.1 or 6.1.2, as appropriate, are met. Note 4The coating thickness grades in Table 1 represent the minimum value obtainabl
22、e with a high level of confidence for the ranges typically found in each material category. While most coating thicknesses will be in excess of those values, some materials in each category may be less reactive (for example, because of chemistry or surface condition) than other materials of the stee
23、l category spectrum. Therefore, some articles may have a coating grade at or close to the minimum requirement shown in Table 1. In such cases, the precision and accuracy of the coating thickness measuring technique should be taken into consideration when rejecting such articles for coating thickness
24、 below that required by this specification. Purchasers desiring a guarantee of heavier coatings than the minimum thicknesses shown herein should use the special requirements (Section 4.1.6) to specify coating thickness grades higher than those shown in Table 1. In addition, the purchaser should anti
25、cipate the need for test batches or extra preparation steps or both, such as blasting before galvanizing or other methods, to attempt to reach the higher requirements with consistency. Some higher-than-standard thicknesses may be impractical or unattainable. 6.2. FinishThe coating shall be continuou
26、s (except as provided below), and as reasonably smooth and uniform in thickness as the mass, size, shape of the item, and necessary handling of the item during the dipping and draining operations at the galvanizing kettle will permit. Except for local excess coating thickness, which would interfere
27、with the use of the product or make it dangerous to handle (edge tears or spikes), rejection for nonuniform coating shall be made only for plainly visible excess coating not related to design factors such as holes, joints, or special drainage problems. (See Note 6.) Since surface smoothness is a rel
28、ative term, minor roughness that does not interfere with the intended use of the product, or roughness that is related to the as-received (ungalvanized) surface condition, steel chemistry, or steel reactivity to zinc shall not be grounds for rejection. (See Note 7.) Surface conditions related to des
29、ign, detailing, or fabrication deficiencies as addressed by ASTM A385/A385M shall not be grounds for rejection. The zinc coating on threaded components of articles galvanized under this specification shall conform to that required in M 232M/M 232. Surfaces that remain uncoated after galvanizing shal
30、l be renovated in accordance with the methods in ASTM A780/A780M, unless directed by the purchaser to leave the uncoated areas untreated for subsequent renovation by the purchaser. 6.2.1. Each area subject to renovation shall be 25 mm 1 in. or less in its narrowest dimension. 6.2.2. The total area s
31、ubject to renovation on each article shall be no more than one half of 1 percent of the accessible surface area to be coated on that article or 26 mm2per kg 36 in.2per ton of piece mass, whichever is less. Note 5Inaccessible surface areas are those that cannot be reached for appropriate surface prep
32、aration and application of repair materials as described in ASTM A780/A780M. Such inaccessible areas, for example, would be the internal surfaces of certain tanks, poles, pipes, tubes, and so forth. 6.2.3. The thickness of renovation shall be that required by the thickness grade for the appropriate
33、material category and thickness range in Table 1 in accordance with the requirements of Section 6.1, except that for renovation using zinc paints, the thickness of renovation shall be 50 percent higher than that required by Table 1, but not greater than 100 m 4.0 mils. 2015 by the American Associati
34、on of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4h M 111M/M 111-9 AASHTO 6.2.4. When areas requiring renovation exceed the criteria previously provided or are inaccessible for repair, the coating shall be rejected. Note 6The requi
35、rements for the finish of a galvanized product address themselves to a visual type of inspection. They do not address the matter of measured coating thickness variations that can be encountered because of different steels or different thicknesses of a given steel being used in an assembly. Note 7Ite
36、ms that are prepared for galvanizing by abrasive cleaning will generally develop a thicker coating with a moderately rougher surface. 6.3. Threaded Components in AssembliesThe zinc coating on external threads shall not be subjected to a cutting, rolling, or finishing tool operation, unless specifica
37、lly authorized by the purchaser. Internal threads are not prohibited from being tapped or retapped after galvanizing. Coatings shall conform to the requirements of M 232M/M 232. 6.4. AppearanceUpon shipment from the galvanizing facility, galvanized articles shall be free from uncoated areas, blister
38、s, flux deposits, and gross dross inclusions. Lumps, projections, globules, or heavy deposits of zinc that will interfere with the intended use of the material will not be permitted. Plain holes of 12.5-mm 1/2-in. diameter or more shall be clean and reasonably free from excess zinc. Marks in the zin
39、c coating caused by tongs or other items used in handling the article during the galvanizing operation shall not be cause for rejection unless such marks have exposed the base metal and the bare metal areas have exceeded allowable maximums from Sections 6.2.1 and 6.2.2. The pieces shall be handled s
40、o that after galvanizing they will not freeze together on cooling. Note 8Depending upon product design or material thickness or both, filming or excess zinc buildup in plain holes of less than 12.5-mm 1/2-in. diameter may occur that requires additional work to make the holes usable as intended. 6.5.
41、 AdherenceThe zinc coating shall withstand handling consistent with the nature and thickness of the coating and the normal use of the article without peeling or flaking. Note 9Although some material may be formed after galvanizing, in general the zinc coating on the articles covered by this specific
42、ation is too heavy to permit severe bending without damaging the coating. 7. SAMPLING 7.1. Sampling of each lot shall be performed for conformance with the requirements of this specification. 7.2. A lot is a unit of production or shipment from which a sample is taken for testing. Unless otherwise ag
43、reed upon between the galvanizer and the purchaser, or established within this specification, the lot shall be as follows: for testing at a galvanizers facility, a lot is one or more articles of the same type and size comprising a single order or a single delivery load, whichever is the smaller, or
44、any number of articles identified as a lot by the galvanizer, when these have been galvanized within a single production shift and in the same bath. For test by purchaser after delivery, the lot consists of the single order or the single delivery load, whichever is the smaller, unless the lot identi
45、ty, established in accordance with the above, is maintained and clearly indicated in the shipment by the galvanizer. 7.3. The method of selection and number of test specimens shall be agreed upon between the galvanizer and the purchaser. Otherwise, the test specimens shall be selected at random from
46、 each lot. In this case, the minimum number of specimens from each lot shall be as follows: 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4h M 111M/M 111-10 AASHTO Number of Pieces in Lot Number of
47、Specimens 3 or less All 4 to 500 3 501 to 1,200 5 1,201 to 3,200 8 3,201 to 10,000 13 10,001 and over 20 Note 10Where a number of identical items are to be galvanized, a statistical sampling plan may be desired. Such a plan is contained in ASTM B602, which addresses sampling procedures for the inspe
48、ction of electrodeposited metallic coatings and related finishes. If ASTM B602 is used, the level of sampling shall be agreed upon between the galvanizer and the purchaser at the time the coating order is placed. 7.4. A test specimen that fails to conform to a requirement of this specification shall
49、 not be used to determine the conformance to other requirements. 8. TEST METHODS 8.1. Test RequirementsThe following tests shall be conducted to ensure that the zinc coating is being furnished in accordance with this specification. The specifying of tests for adhesion and embrittlement shall be subject to mutual agreement between the galvanizer and purchaser. Visual inspection of the coating shall be made for compliance with the requirements. 8.2. Thickness of Coating TestThe thickness of coating is determined by one or
