ASTM WK75029

    New Specification for Carbon Steel Laser and Laser-Hybrid Welded, Sharp Cornered Profile (SCP), Built-Up, Square, Rectangular and Special Shape Tube

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    Developed by Subcommittee: A01.09 | Committee A01 | Contact Staff Manager



    WK75029

    1. Scope

    1. Scope * 1.1This specification covers laser beam or laser hybrid welded, built-up, carbon steel sharp cornered profiles (SCP) square, rectangular, or special shape structural tubing for welded, riveted, or bolted construction. SCP tubing is utilized in but not limited to the following applications: buildings and structures, including architecturally exposed steel structures (AESS), architectural steel profiles such as curtain wall, staircases, and others; industrial; and general structural applications. Note 1: There is no standard for other sharp cornered laser or laser hybrid welded carbon steel structural shapes. Appendix A provides guidance on the specification of built-up carbon steel laser and laser-hybrid welded beams, tees, channels, angles and custom shapes. 1.2 The structural hollow sections produced to this specification with a periphery of 112 in. [2845 mm] or less, and a specified wall thickness of 1.000 in. [25.4 mm] or less. 1.3 This specification establishes the minimum requirements for manufacturing of sharp cornered laser welded carbon steel hollow sections and requires the welds to, at minimum, match the strength of the base metal. NOTE 2: Product covered by this standard is manufactured in small runs on dedicated production lines. Requiring the lot testing that is done on large runs of identical structural tubing products would impose an unreasonable cost burden. Quality requirements for the standard products produced to this specification are instead ensured through qualification in accordance with AWS, ISO or CSA requirements. When required, Supplementary S1 tensile, S2 bend, and S3 Charpy-V Notch lot testing can be specified. NOTE 3: Due to the varying requirements of the end use applications, four different levels of dimensional tolerance and weld inspection requirements can be specified. 1.4 This specification refers to Specifications A36/A36M, A572/A572M, EN 10025-2 or EN 10025-3 for chemical requirements and for the base and weld metal mechanical test requirements of the designated strength grade. 1.5 The text of this specification contains notes and footnotes that provide explanatory material. Such notes and footnotes, excluding those in tables and figures, do not contain any mandatory requirements. 1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.


    Keywords

    rectangular tube; square tube; special shape; sharp cornered; built-up; laser weld; laser-hybrid weld; fusion welding; carbon steel; AESS; SCP; architectural steel; architectural steel profiles.

    Rationale

    The scope of AWS D1.1 states, This code contains the requirements for fabricating and erecting welded steel structures but it does not cover dedicated production methods for structural shapes. Architectural and industrial applications are increasingly using short runs of precision, built-up, Sharp Cornered Profile (SCP), laser- and laser-hybrid steel tube products from dedicated production lines, particularly when aluminum doesnt satisfy the structural requirements. SCP steel tube sections are used when the round corners of standard tubular products do not satisfy the dimensional requirements. The applications include life safety critical curtain wall, window mullion, egress stairs and industrial applications. The abbreviation SCP is commonly used when specifying this product. In a series of emails in 2019, Mr. Elhert of Novum Structures, a fabricator who purchases the product, communicated the need for this ASTM standard, while mentioning that a standard already exists for laser and laser-hybrid welded stainless steel (ASTM A1069/A1069M). His firm provided a letter of support, feedback on draft development and has requested the addition of Canadian Standards Association CSA W47.1. US, Canadian and European fabricators and US and European manufacturers are formally requesting this standard and there have also been requests from structural engineers using this product. European and US manufacturers of this product, Montanstahl and Stainless Structurals significantly contributed to the draft. Additional fabricators who purchase SCP steel, specifically TriPyramid, Feature Walters, Haskell, Newport Industrial Fabrication, Sentech, Seele, Roshmann Group, and Mistral Architectural Metal & Glass, have written letters of support. This is the first ballot of the draft Currently, some are specifying carbon steel to ASTM A1069/A1069M, which is for laser and laser hybrid welded stainless steel, due to the lack of a carbon steel standard, which is problematic. ANSI/AISC 360 provides the expected weld design strength but does not limit the welding methods that can be used for SCP products or establish quality requirements. Simply referencing AWS D1.1, ISO or CSA W47.1 (Canada) is not sufficient to define the requirements for SCP tube. This standard will fill the existing specification gap. The stainless steel standard, ASTM A1069 was used as the starting point for this draft. The ISO, CSA and AWS standards for laser and laser hybrid operator and process qualification apply to all steels and, since users of the standard may not have these documents for reference but may want to understand their requirements, they have been summarized in Appendix X2. Referencing them avoids a conflict between standards and unnecessary standard length while capitalizing on standard setting body expertise. While these standards set welding qualification requirements, final product dimensional tolerances, inspection and other requirements are equally important in producing a high quality structural shape. Because this is a short run, customized product, some of the requirements for large production runs of carbon steel tube are not applicable such as continuous identification marking. Raw material is purchased to the chemistry requirements of other standards. Custom laser and laser hybrid carbon steel structural shapes other than tube are purchased so a non-mandatory appendix provides guidance for specifiers of these products since it has been determined that there is currently no A01 subcommittee that is an appropriate fit for a standard covering these products.

    The title and scope are in draft form and are under development within this ASTM Committee.

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    Work Item Status

    Date Initiated:
    12-02-2020

    Technical Contact:
    Catherine Houska

    Status:
    Draft Under Development