Many of the defects in stainless steel welds are due to lack of care or inadequate supervision to ensure that the weld procedures have been correctly prepared, understood and then followed.  The consequences of weld defects may be an irritation about cosmetic effects but the use of stainless steel, and especially the higher alloys, implies that there will be consequences if the welding fails.  Structural, pressure  vessel and hygienic welding standards all list defects and set limits to the extent of both the surface breaking and subsurface defects but without alluding to why they occurred and their effects on service.  And metallurgical issues or heat tint and its effects? They are part of the welder qualification and the technique to be followed by the welder to satisfy the test.

The ethos of the first session webinar on 15 Jan 2021 is to pick out defects or difficulties, explain how they can be detected (from visual to instrumental techniques), why it occurred and then how to correct it and learn for next time.  Some defects are permitted but the limits on number and sizes are there for good reasons which will be explored. This is not a basic welding course but it will cover items like preparation differences for various stainless steels, heat input, gas mixtures, purging and its precautions, the difficulties of restrained joints and the differences between welding austenitic, ferritic and duplex alloys.  A number of specifics will be briefly examined including welding 6% moly or fully austenitic alloys, when sigma phase effects might occur and the very different experiences in welding old and new ferritic alloys.

Issues raised before the webinar will be slotted in as much as possible or can be raised at the Q&A session.  The second session in 26 February 2021 will deal with items including dissimilar metal welding, amplify on metallurgical issues not covered such as repair welding of aged components and look at the differences in weld quality and post-weld processing required by different end uses.