ISO TR 17671-2-2002 pdf free download.Welding — Recommendations for welding of metallic materials — Part 2: Arc welding of ferritic steels.
8 Weld details
8.1 Butt welds Butt joints between parts of unequal cross-section should be made and subsequently shaped such that a severe stress concentration at the junction is avoided.
Some examples of joint preparations for use with metal-arc welding with covered electrodes and gas-shielded metal-arc welding are given in ISO 9692-1. Partial penetration butt joints may be permitted dependant on the design specification. Consideration should be given to the choice of weld preparation and welding consumables in order to achieve the specified throat thickness. Under fatigue conditions, partial penetration joints or the use of permanent backing material may be undesirable.
Backing material may consist of another steel part of the structure when this is appropriate.
When it is not appropriate to use part of the structure as backing material, the material to be used should be such that detrimental effects on the structure are avoided and should also be agreed in the design specification. Care should be taken when using copper as a backing material as there is a risk of copper pick-up in the weld metal. Where temporary or permanent backing material is used, the joint should be arranged in such a way as to ensure that complete fusion of the parts to be joined is readily achieved. Wherever the fabrication sequence allows, tack welds, attaching permanent backing should be positioned for subsequent incorporation into the weld (see clause 14 of ISO/TR 17671-1:—).
8.2 Fillet welds Unless otherwise specified, the edges and surfaces to be joined by fillet welding should be in as close contact as possible since any gap may increase the risk of cracking. Unless otherwise specified, the gap should not exceed 3 mm.
Consideration should be given to the need to increase the throat of the fillet weld to compensate for a large gap. Unless otherwise specified, welding should not start/stop near corners, instead, it should be continued around the corners.
9 Welds in holes or slots Due to the risk of cracking, holes or slots should not be filled with weld metal unless required by the design specification. Holes or slots that are required to be filled with weld metal shall only be filled after the first run has been found to be acceptable (see also B.4).
10 Preparation of joint face
10.1 General Any large notches or any other errors in joint geometry which might occur should be corrected by applying a weld deposit according to an approved welding procedure. Subsequently, they should be ground smooth and flush with the adjacent surface to produce an acceptable finish. Prefabrication primers (shop primers) may be left on the joint faces provided that it is demonstrated that they do not adversely affect the welding.ISO TR 17671-2 pdf download.