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.
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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. Common distorted and warped members of assemblies are sheets or astm a384 assembled by welding or riveting.
Referenced Documents purchase separately The documents listed below are referenced within astm a384 subject standard but are not provided as part of the standard.
ASTM A Recommendations | American Galvanizer’s Association
Historical Version s – view previous versions of standard. This abstract is a astm a384 summary of the referenced standard. Avoid Susceptible Thin Sheet Steels Steel invariably contains internal stresses induced at the mill from rolling operations used to bring structures, plate, and sheet astm a384 the final astk.
Minimize Thick and Thin Material in the Same Assembly When two astm a384 of different thicknesses are assembled and brought up to galvanizing temperature, the thinner steel heats up and expands more quickly than the thicker steel.
Within the text of this specification and where appropriate, SI units are shown in parentheses. Furthermore, cylindrical structures are less likely to warp or distort than rectangular or elliptical ones. This specification deals with safeguarding against warpage and distortion during hot-dip astm a384 of steel assemblies. astm a384
ASTM A384 Recommendations
Asymmetrical Design Symmetrical sections such as I-beams and astm a384 will be less likely to astm a384 than asymmetrical pieces camber beams, channels, tees, custom beams, girders because the thermal expansion forces above and below the natural axes balance each other. The following can cause warpage and distortion: Steel invariably contains internal stresses induced at the mill from rolling operations used to bring structures, plate, and sheet to the final thickness.
Additionally, the installation of diagonal members should be performed after galvanizing. Therefore, steel thicknesses should vary as little as astm a384 throughout the assembly. Welding results in significant residual stress in small areas of an assembly due astm a384 the extreme temperature differences experienced.
Suggested corrections for panel fabrication are detailed.
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.
Oftentimes sheet or plate can be returned to a flattened state using a jig or astm a384 weighing the product down on a flat surface astm a384 the astm a384. Link to Active Astm a384 link will always route to the current Active version of the standard. The design and fabrication of the product to be galvanized are the responsibilities of the designer and the fabricator. 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 astm a384 stresses completely.
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. 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. 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.
Standard: ASTM A384
After galvanizing, these products should be air cooled instead of quenched to minimize induced stress from the cooling cycle. 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.
The overall amount of welding can be minimized by astm a384 bolted connections or performing assembly after hot-dip galvanizing. Optimize Welding Before Hot-Dip Galvanizing Welding results in significant residual stress in small areas of an assembly due astm a384 the astm a384 temperature differences experienced.
Inch pounds and SI units are not necessarily exact equivalents.
The following displays various methods to reduce or eliminate the potential for warpage and distortion. Specify symmetrically rolled astm a384 instead of angle or channel frames. 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. Wherever possible, galvanize thick and thin astm a384 separately and join them after galvanizing.