This Standard specifies requirements for the welding of steel structures made up of combinations of steel plate, sheet or sections, including hollow sections and built-up sections, or castings and forgings, by the following processes:Manual metal-arc welding (MMAW).Submerged arc welding (SAW).Gas metal-arc welding (GMAW), including pulsed mode.Gas tungsten-arc welding (GTAW or TIG).Flux-cored arc welding (FCAW).Electroslag (including consumable guide) welding (ESW) (see Note).Electrogas welding (EGW) (see Note). These processes may not be suitable for welding quenched and tempered steels in all cases (see WTIA Technical Note 15).The Standard is limited to the welding of quenched and tempered steel parent material complying with Clause 2.1.The Standard applies to the welding of steelwork in structures complying with appropriate Standards. Where welded joints in these structures are governed by dynamic loading conditions, the Standard applies only to those welded joints that comply with the fatigue provisions of AS 3990, as limited by Item (ii) below, or with the directly equivalent fatigue provisions of other application Standards.The Standard applies to welded joints that are-(i)not subject to fatigue conditions; or(ii)subject to fatigue conditions; and-(A)the stress range in the welded joint complies with the permissible stress range of stress Categories C, D, E or F of AS 3990, or weld categories lower than or equal to detail Category 112 of AS 4100 or NZS 3404.1; or(B)the stress range in the welded joint is not greater than 80% of the permissible stress range of stress Category B of AS 3990 (Category SP weld, see Clause 1.5.2); or(C)the stress range in the welded joint is greater than 80% of the permissible stress range for stress Category B of AS 3990, or exceeds the stress range permitted for detail Category 112 of AS 4100 or NZS 3404.1 (Category FP weld, see Clause 1.5.2), but does not exceed the maximum stress ranges permitted for these categories.In addition to the abovementioned structures, the Standard applies to the welding of bridges, cranes, hoists, earthmoving equipment, other dynamically loaded structures and steelwork in applications other than structural.Further information on this Standard is given in WTIA Technical Note 11.Complementary codes that facilitate design and fabrication of high strength quenched and tempered steels include the following:American Institute of Steel Construction Specification for the Design, Fabrication and Erection of Structural Steel for Buildings.American Association of State Highway and Transportation Officials, Standard Specifications for Highway Bridges.American Railway Engineering Association Specifications for Steel Railway Bridges.The Standard requires that weld preparations, welding consumables and welding procedures be qualified before commencement of welding. Prequalified joint preparations, welding consumables and welding procedures are also given in the Standard.In catering for structures subject to fatigue conditions as well as statically loaded structures, the Standard provides three categories of welds with three differing levels of weld quality assurance associated with the different types of service to which the welds are subjected. The intention is for the designer to elect the category suited to the severity of the service and nominate this on the drawings. Where a structure contains more than one category, this will ensure that appropriate levels of supervision and inspection will be applied to the relevant parts of the structure.

First published as AS 1554.4-1989.Jointly revised and designated AS/NZS 1554.4:1995.Third edition 2004.Fourth edition 2010.