There are precautions provided in ASTM A/AM that should be considered to prevent embrittlement, as well as selecting steels with appropriate. Practice ASTM A provides guidance on safeguarding against warpage and be stress relieved per the guidelines provided within ASTM A, Section 6. ASTM A / AM Standard Practice for Safeguarding Against Embrittlement of Hot-Dip Galvanized Structural Steel Products and Procedure.
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ASTM A384 Recommendations
Wherever possible, galvanize thick and thin portions separately and join them after galvanizing. This specification covers cold-formed welded and seamless carbon steel round, square, rectangular, or special shape structural tubing for welded, riveted, or bolted construction of bridges and buildings, and for general structural purposes.
A requires a continuous, smooth, and uniform finish with no uncoated areas including on the threads or issues that interfere with its intended use. Specification for Structural Steel. Inch-pounds and SI aastm are not necessarily exact equivalents. Was this answer helpful?
The specification requirements for coating thickness only contain minimums, there is no maximum coating thickness limitation in the specification. The requirements of this specification are very similar to those in A, except for the addition of threaded products and embrittlement requirements. Embrittlement is not a common occurrence, however, and this discussion does not imply that galvanizing increases embrittlement where good fabricating and galvanizing procedures are employed.
Steel invariably contains internal stresses induced at the mill from rolling operations used to bring structures, plate, and sheet to the final thickness.
ASTM A Recommendations | American Galvanizer’s Association
The LCC analysis considers not only the initial cost of the system but also the future costs maintenance, replacement, etc. The following is a summary of the various pertinent hot-dip galvanizing specifications.
Xstm a copy from zstm AGA, or asstm your local galvanizer. Are you an Engineering professional? That’s a standard for safeguarding against embrittlement of hot-dip galvanized steel.
Within the text of this practice and where appropriate, SI units are shown in brackets. The purpose of the calculation is to provide justification for the purchase of a higher initial cost system with a low life-cycle cost over an initially less expensive coating which has high future costs. Any combination of these products can be assembled into a single fabrication and then hot-dip galvanized. The design of the product and selection of proper steel for its suitability to withstand normal galvanizing operations is the responsibility of the designer and fabricator.
LME grade, special high grade, high grade, intermediate grade, and prime western grade. The adherence requirement is the same as A, for strong bond throughout the life of the hot-dip galvanized steel.
By joining you are opting in to receive e-mail. Students Click Here Join Us! Standard Specification for Zinc.
ASTM A143/A143M – 07(2014)
Where welding before galvanizing cannot be avoided, the internal stresses in the connections can be minimized by avoiding joint designs or weld lengths which are greater than statically required, and by placing welds near to and symmetrically around the neutral axis – aa143 welds so that shrinkage and opposing forces are balanced rather than all pulling in the same direction. Link to Active This link will always route to the current Active version of the standard.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. Requirements concerning the renovation of uncoated areas after initial hot-dip galvanizing are contained within the material specifications A, A, A The material categories covered in the specification include structural steel and plate, strips and bars, pipes and tubing, and wires.
A second type asym embrittlement, hydrogen embrittlement, is recognized when stresses are asmt to the steel in use. LME grade, special high grade, high grade, intermediate grade, and prime s143 grade. This specification covers zinc metal made from ore or other material by a process of distillation or by electrolysis in five grades as follows: This specification covers the requirements for hot-dip zinc coating applied to carbon steel and alloy steel bolts, screws, washers, nuts, and special threaded fasteners applied by the hot-dip coating process.
Inch-pounds and SI units are not necessarily exact equivalents. I’m reading through stacks of specs for a project we’re bidding and in the galvanizing spec one of the many lines says that ASTM A shall govern.
Practice ASTM A provides guidance on safeguarding against warpage and distortion for optimum hot-dip galvanizing and shall be complied with in both design and fabrication. This practice is applicable to chromate coatings of the colorless both one and two-dipiridescent yellow or bronze, olive drab, black, colorless anodic, yellow or black anodic types, and of the dyed variety, when applied to surfaces of electrodeposited zinc, mechanically deposited zinc, hot-dipped zinc, rolled zinc, electrodeposited cadmium, or mechanically deposited coatings.
Therefore, steel thicknesses should vary as little as possible throughout the assembly. Click Here to join Asttm and talk with other members! Avoid Susceptible Thin Sheet Steels Steel invariably contains internal stresses induced at the mill from rolling operations used to bring structures, plate, and sheet to the final thickness. First, the specification details the coating thickness requirements based on bar size. The requirements for finish, appearance, and adherence are identical to those in the other main standards.