AWS D17.2／D17.2M pdf free download

AWS D17.2／D17.2M pdf free download.Resistance Welding for Aerospace Applications.
3. Terms and I)efinitions
AWS A3.OM/A3.O. Siandard Welding Terms and Definilions. including Terms for Adhesive Bonding. Bracing, Soldering. Thermal Culling, and Thermal Spraying, provides the basis for terms and definitions used herein. However. the following terms and definitions are included below to accommodate usage specific to this document.
close-spaced welds. Spot welds on sheet placed less than two diameters apart. center to center. Such proximity may require more power than other spot welds.
coring. Incipient melting adjacent to the nugget.
Engineering Authority. The contracting agency or corporation that acts for and in behalf of the customer on all matters within the scope of this standard. The Engineering Authority has responsibility for the structural integrity or maintenance of airworthiness of the hardware and compliance with all contract documents.
fabricator. The organiiation responsible for producing weldments that satisfy the design and contract requirements. foil. A material having thickness of 0A)8 in [0.2 mrnj or less.
metallographic section. A transverse cut on the diameter of a spot weld or across a seam weld, or a longitudinal cut down the center of a seam weld, polished down w near the center of the weld and etched to accentuate the metallographic structure.
nugget. The weld (fused) metal joining the parts in spot. seam, or projection welds.
resistance weld size. The diameter of a spot weld nugget or the width of a seam weld nugget measured at the plane of the faying surfaces.
peel test. A mechanical test in which the corners (or sides) of seam or spot welded foil or sheet members are gripped and pulled apart to determine if the joint fails by delamination, by fracture of a cleaved surface, or by tearing of a button (plug) out of the parent material. Delamination, in contrast to fracture, is a sign of no fusion between the two adjacent members. A button or plug. which is pulled out of the removed member, is not necessarily equal in size to the cast nugget underlying it.
penetration. The extent of the nugget (fusion zone) into the thickness of a joined member.
4. Requirements
4.1 Design Requirements
4.1.1 Definition of terms used in this specification shall he in accordance with AWS A3.OM/A3.0, AWS A2.4, and as shown in Clause 3 herein.
4.1.2 The Engineering Authority shall be responsible for the development of the contract specification that governs products or structural assemblies produced under this specification. The Engineering Authority may add to, delete from, or otherwise modify, the requirements of this specification to meet the particular requirements of a specific structure. All requirements that modify this specification shall be incorporated into contract documents, engineering drawings, or item specifications. The Engineering Authority shall determine the suitability of all joint details to be used in a welded assembly.
4.1.3 When conditions are encountered_which cause any of the requirements_of this_specification obe unaltainahlç1 the fabricator may submit alternate procedures and requirements for approval by the Engineering Authority.
4.1.4 The class of welding shall be designated on the item specification or drawing. In the event of any conflict between the requirements of this specification and those requirements specified on the engineering drawing, the engineering drawing shall prevail.
4.1.5 Spot Weld Certification. There shall be two methods of certification for spot welds.
4.1.5.1 Standard Certification. The standard certification method shall be for a weld schedule that certifies to the requirements of Tables I through 3 (sheet) or Table 4 (foil), and all other applicable weld property requirements listed in this specification have been met.
4.1.5.2 I)esign Allowable Certification. The design allowable certification method shall he used for a weld schedule that certifies a guaranteed minimum strength value or nugget size specified on the engineering drawing has been met. Conditions where design allowable certification shall he permitted are: where available space, equipment, or material conditions and design stress permits the use of smaller or lower strength welds: where weld conditions and design stress require larger or higher strength welds: or where unusual conditions exist (such a.s welding through adhesives or surface coatings). When design allowable certification is used, the guaranteed strength value or nugget size and weld class shall he specified on the engineering drawing.AWS D17.2／D17.2M  pdf download.