This standard is issued under the fixed designation A/AM; the number 1 This practice is under the jurisdiction of ASTM Committee A05 on Metallic-. In all cases only the current version of the standard as published by ASTM is to be considered the official document. Designation: A – 76 (Reapproved ) . ASTM A – A M – 02 – Download as PDF File .pdf), Text File .txt) or read online.
|Published (Last):||10 September 2015|
|PDF File Size:||4.61 Mb|
|ePub File Size:||12.29 Mb|
|Price:||Free* [*Free Regsitration Required]|
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 – aligning welds so that shrinkage and opposing forces are balanced rather than all pulling in the same direction. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application.
When two steels of different thicknesses are assembled and brought up to galvanizing temperature, the thinner steel heats up and expands more quickly than the thicker steel. Wherever possible, galvanize thick and thin portions separately and join them after galvanizing. Last previous edition A – After galvanizing, these products should be air cooled instead of quenched to minimize induced stress from the cooling cycle. It is recommended that welding procedures be carried out in conformancewith the pertinent specificationsof the American Welding Society.
The following can cause warpage and distortion: This will prevent the rusting of the surfaces which are so connected that molten zinc cannot circulate through the crevices to galvanize the contacting surfaces. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
A superscript epsilon E indicates an editorial change since the last revision or reapproval.
ASTM A Recommendations | American Galvanizer’s Association
All efforts should be made to keep the stresses in the construction as low as possible right from the beginning to enable the steel to absorb the internal stresses completely. Specify symmetrically rolled sections instead of angle or channel frames. Originally published as A – 55 T. 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.
A number in parentheses indicates the year of last reapproval.
ASTM A _图文_百度文库
Historical Version s – view previous versions of standard. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters. Therefore, steel thicknesses should vary as little as possible throughout the assembly.
Clamps may be applied to prevent shifting or movement during the welding operation. In the case of sheet metal, the product which has a right-angle bend in the sheet metal itself will remain flatter and be freer from distortion if the radius of the bend is as large as practicable. Inch pounds and SI units are not necessarily exact equivalents.
Factors in Warpage and Distortion 3. Optimize Welding Before Hot-Dip Galvanizing Welding results in significant residual stress in small areas of an assembly due to the extreme temperature differences experienced.
This abstract is a brief summary of the referenced standard. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
The overall amount of welding can be minimized by using bolted connections or performing assembly after hot-dip galvanizing. Where excessive cold working or tight bend radii cannot be avoided, the product should be stress relieved per the guidelines provided within ASTM A, Section 6.
Suggested Corrections for Panel Fabrication 4.
I the f frame has to be dipped one half at a time, it asym be better to have the sheets galvanized, rolled flat after galvanizing, and assembled to the galvanized frame by the use of aluminum alloy or galvanized rivets. Furthermore, cylindrical structures are less likely to warp or distort than rectangular or elliptical ones. Steel invariably contains internal stresses induced at the mill from rolling operations used to bring structures, plate, and sheet to the final thickness.
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. Necessary precautions to fabricate astk and prepare the material for galvanizing to prevent embrittlement are described in Practice A Link to Active This link will always route to the current Active version of the standard.
Suggested corrections xstm panel fabrication are detailed.
ASTM A384 Recommendations
Oftentimes sheet or plate can be returned to a flattened state using a jig or by weighing 3a84 product down on a flat surface during the cool-down. The design and fabrication of the product to be galvanized are the responsibilities of the designer and the fabricator. This specification deals with safeguarding against warpage and distortion during hot-dip galvanizing of steel assemblies. Symmetrical sections such as I-beams and tubing will be less likely to distort than asymmetrical pieces camber beams, channels, tees, custom beams, girders because the thermal expansion forces above and below the natural axes balance each other.
Channels and other nonsymmetrical sections should be avoided for asttm framework of a sheet metal assembly that is to be hot-dip galvanized whenever it is possible to use symmetrical shapes or sections.
Current edition approved Oct. Within the text of a3384 specification and where appropriate, SI units are shown in parentheses.