ISO 5817:2014 pdf download – Welding — Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded) — Quality levels for imperfections.
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.