AS NZS ISO 5817 pdf download

AS NZS ISO 5817 pdf download.Welding—Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded) – Quality levels for imperfections
1  Scope
This International Standard provides quality levels of imperfections in fusion-welded joints (except for beam welding) in all types of steel, nickel, titanium and their alloys. It applies to material thickness ≥ 0,5 mm. It covers fully penetrated butt welds and all fillet welds. Its principles can also be applied to partial-penetration butt welds. (Quality levels for beam welded joints in steel are presented in ISO 13919-1.) Three quality levels are given in order to permit application to a wide range of welded fabrication. They are designated by symbols B, C and D. Quality level B corresponds to the highest requirement on the finished weld. Several types of loads are considered, e.g. static load, thermal load, corrosion load, pressure load. Additional guidance on fatigue loads is given in Annex C. The quality levels refer to production and good workmanship. This International Standard is applicable to a) non-alloy and alloy steels, b) nickel and nickel alloys, c) titanium and titanium alloys, d) manual, mechanized and automatic welding, e) all welding positions, f)  all types of welds, e.g. butt welds, fillet welds and branch connections, and g)  the following welding processes and their sub-processes, as defined in ISO 4063: —  11 metal-arc welding without gas protection; —  12 submerged-arc welding; —  13 gas-shielded metal-arc welding; —  14 gas-shielded arc welding with non-consumable tungsten electrodes; —  15 plasma arc welding; —  31 oxy-fuel gas welding (for steel only). Metallurgical aspects, e.g. grain size, hardness, are not covered by this International Standard.
3  Terms and definitions
For the purposes of this document, the following terms and definitions apply. 3.1 quality level description of the quality of a weld on the basis of type, size and amount of selected imperfections 3.2 fitness-for-purpose ability of a product, process or service to serve a defined purpose under specific conditions 3.3 short imperfections <weld 100 mm long or longer> imperfections whose total length is not greater than 25 mm in the 100 mm of the weld which contains the greatest number of imperfections 3.4 short imperfections <weld less than 100 mm long> imperfections whose total length is not greater than 25 % of the length of the weld 3.5 systematic imperfections imperfections that are repeatedly distributed in the weld over the weld length to be examined, the size of a single imperfection being within the specified limits 3.6 projected area area where imperfections distributed along the volume of the weld under consideration are imaged two-dimensionally Note 1 to entry: In contrast to the cross-sectional area, the occurrence of imperfections is dependent on the weld thickness when exposed radiographically (see Figure 1). 3.7 cross-sectional area area to be considered after fracture or sectioning 3.8 smooth weld transition even surface with no irregularities or sharpness at the transition between the weld bead and the parent material 3.9 fatigue class FATx classification reference to S-N curve, in which x is the stress range in MPa at 2· 10 6 cycles Note 1 to entry: Fatigue properties are described by S-N-Curves (Stress-Number of cycle- curves). Note 2 to entry: See Annex C.
5  Assessment of imperfections
Limits for imperfections are given in Table 1. If, for the detection of imperfections, macro-examination is used, only those imperfections shall be considered which can be detected with a maximum of tenfold magnification. Excluded from this are micro lack of fusion (see Table 1, 1.5) and microcracks (see Table 1, 2.2). Systematic imperfections are only permitted in quality level D, provided other requirements of Table 1 are fulfilled. A welded joint should usually be assessed separately for each individual type of imperfection (see Table 1, 1.1 to 3.2). Different types of imperfection occurring at any cross-section of the joint need special consideration (see multiple imperfections in Table 1, 4.1). The limits for multiple imperfections (see Table 1) are only applicable for cases where the requirements for a single imperfection are not exceeded. Any two adjacent imperfections separated by a distance smaller than the major dimension of the smaller imperfection shall be considered as a single imperfection.