Preface
This is the eighth edition of CSA Standard W59, Welded Steel Construction (Metal Arc Welding). It supersedes the previous editions published in 1989, 1984, 1982, 1977, 1970, 1946, and 1940. Unlike the 1989 edition, which was published separately in yard/pound (imperial) and SI (metric) versions, the 2003 edition consolidates the units. SI (metric) units govern in this eighth edition. Comparable approximate imperial units are provided in parentheses, where applicable, and are included only for information purposes. All text, tables, and figures in this edition have been completely reformatted electronically.
The following is a brief description of some of the most significant changes to the present W59 Standard.
The Scope of the Standard is covered in Clause 1. Changes to the Scope reflect the renaming of Clause 12 from Dynamically Loaded Structures to Cyclically Loaded Structures, to better reflect the emphasis of Clause 12 on the repetitive nature of structural loadings (fatigue) rather than the rate at which the loading is applied. Clause 1 acknowledges that provisions for metal-cored arc welding are now included in the Standard. Clause 1 also more clearly defines the application of the Standard, which is to base metals 3 mm and thicker. AWS D1.3 is recognized for welding thinner steels. Clause 1 also acknowledges the need for safety in welding, which is covered by other Standards.
In Clause 2, consumables manufactured to deposit weld metal having a specified maximum limit of diffusible hydrogen have been redefined as low hydrogen, instead of being referred to as basic. Two forms of engineering responsibility are also introduced: the Engineer responsible to the Contractor and the Engineer acting on behalf of the Purchaser or regulatory authority.
The qualification requirements for contractors performing work under this Standard have been moved to Clause 3 from Clause 6. Clause 3 also acknowledges that joints welded by either metal-cored arc or gas metal arc, in the spray transfer mode, can now be deemed as prequalified. Several steels have been added to the prequalified list.
In Clause 4, Design of Welded Connections, complete joint penetration groove welds are now designated as CJP and partial joint penetration groove welds as PJP. Fillet welds are now defined as having included angles between fusion faces of 60° to 135°. The section on flare welds has been completely rewritten and expanded significantly to cover flare bevel and flare V-groove welds in butt joints, and flare bevel groove welds in T-Joints. The concept of a flare bevel fillet weld is introduced. Minor changes have been introduced into the Section on plug and slot welds. A new clause dealing with skewed joints has been added.
Clause 5 has been reworded to reflect low hydrogen terminology and the inclusion of metal-cored arc welding. The section on storing and conditioning of electrodes has been rewritten. Information regarding beam copes and weld access holes is now included in the Standard along with special requirements for Group 4 and 5 shapes. The section on stud welding has been reworked.
Clause 6 has been left open, as the content was moved to Clause 3.
In Clause 7, CSA Standard W178.1, CSA Standard W178.2, and AWS QC1 are recognized.
In Clause 8, the radiographic portion has been rewritten, and procedures now include the use of hole type IQIs and wire type IQIs.
Clause 9, Strengthening and Repair of Existing Structures, has been completely rewritten. More emphasis has been placed on stress analysis, workmanship, and the need for a comprehensive work plan including inspection and documentation. Methods of fatigue life enhancement have been recognized.
In Clause 10, all the figures have been reviewed for consistency. A major inclusion is the prequalified joint geometries for the metal-cored arc welding process and the gas metal arc welding process, when using spray transfer. In addition, prequalified geometries have been included for various flare welds. Also, three previously qualified SMAW partial joint geometries have been deleted, M1-1P, M2-1P and M4-1P. The effective throats of two other SMAW partial joint geometries have been reduced M1-2P and M1-3P.
Clause 11, for statically loaded structures, has seen limited changes. The allowable stress method of design has been retained for this edition, but with no meaningful changes from the prior edition. Changes have only been made to the limit states design method. The strength of fillet welds can now be increased, depending upon the direction of loading. Partial penetration joints loaded in tension normal to the axis of the weld are no longer assumed to be loaded in shear.
The title of Clause 12 has been changed to Cyclically Loaded Structures — Design and Construction, to more accurately reflect the emphasis in the clause on the effects of cyclic and repetitive loadings (fatigue) on structures, rather than the rate at which the load is applied. The previous step-function allowable range of stress for various fatigue details has been replaced by a continuous equation. Fatigue is recognized as being load-induced or distortion-induced. The use of Miner’s Rule is introduced for assessing cumulative damage from variable amplitude loading. Methods to enhance the fatigue resistance of welds are recognized. Additional fatigue detail categories have been added.
As CSA W59 contains no commentary, various nonmandatory appendices have been included to generate a better understanding of certain aspects of welded steel construction. The appendices of the previous edition of W59 have generally been reviewed for clarity.
Appendix H, which is a mandatory appendix dealing with the qualification of studs, has seen significant changes.
Appendix K has been modified to reflect only the results of research on arc spot welds.
Appendix L has been completely rewritten to reflect the importance of hollow structural sections in welded construction and the need for a better understanding of the design of their connections.
The previous Appendix N on weld capacities, loaded in shear has been deleted and replaced with an appendix providing a better understanding of the modes of metal transfer in gas metal arc welding, especially in light of the prequalification of joints using the spray transfer mode.
Appendix P has seen minor clarification changes regarding alternative preheat determination.
Appendix R has been added to provide a better understanding of the new equations dealing with the fatigue assessment of structures and the methods of fatigue life enhancement.
This Standard was prepared by the Technical Committee on Welding of Bridges, Buildings, and Machinery, under the jurisdiction of the Strategic Steering Committee on Welding and Structural Metals, and has been formally approved by the Technical Committee.
Scope
1.1
This Standard covers welding requirements for carbon and low-alloy welded steel construction, with the exception of those types listed in Clause 1.2. Requirements that are essentially common to all such structures are covered in Clauses 1 to 10, while provisions applying specifically to statically loaded structures and to cyclically loaded structures are included in Clauses 11 and 12, respectively.
1.2
This Standard is not intended to apply to pressure vessels or to structures governed by special codes such as those of Lloyds, the American Petroleum Institute, the American Society of Mechanical Engineers, or the American Water Works Association. This Standard does not cover welding of stainless steel.
Note: When welding stainless steel, other standards such as AWS D1.6 could be referenced.
1.3
This Standard includes provisions for shielded metal arc welding (SMAW), submerged arc welding (SAW), gas metal arc welding (GMAW), flux-cored arc welding (FCAW), metal-cored arc welding (MCAW), electroslag welding (ESW), electrogas welding (EGW), and stud welding (SW) processes.
1.4
The provisions of this Standard are not intended for use with steels having a specified minimum yield strength over 700 MPa (100 000 psi).
1.5
This Standard applies to the welding of base metals 3 mm (1/8 in) and thicker. In cases where base metals less than 3 mm (1/8 in) thick are to be welded to base metals 3 mm (1/8 in) and thicker, the requirements of AWS D1.3 and this Standard apply. In the case of any conflict between AWS D1.3 and this Standard, the requirements of this Standard govern. Note: In cases where base metals less than 3 mm (1/8 in) thick are to be welded to base metals less than 3 mm (1/8 in), the requirements of AWS D1.3 may be appropriate.
1.6
The values given in SI (metric) units are the standard. The values given in parentheses are for information only.
1.7
This Standard does not purport to address safety problems associated with welding and welding practices.
Note: CSA Standard W117.2 addresses safety in welding, cutting, and allied processes, and should be followed in addition to any applicable workplace health and safety legislation in effect. It is the responsibility of the user of this Standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.
