WP4 Face to Face #6, Oxford 14 th July 2011 Welding summary Richard French – The University of Sheffield

Welding progress – materials 316L in 1/8” programme complete – to write up. 316L in 2.0mm OD – back burner but will fit in CP2 Ti in 1/8” 70% done – need to collate NDT and DT results, double check and write up. CP2 Ti in 2.275mm OD – there are problems and some are more fundamental than others.

Weld system update Original M200 procurement spec – met the baseline of 316L Stainless Steel in 1/8” with a wall thickness of 0.22mm which has been met. M200 failed before outside upgrade week at Oxford. Mechanical problems fixed and CPU problems also fixed. New software was not so good. Repeated trips to Warrington to callibrate the weld system to the old settings. This is now done (5 th July) and working correctly. New software ready in September – patches made to fix some pretty serious problems found. Big error from manufacturers to release. Cost us at least 3 months, revisiting old measurements and verifying weld programmes. Collets are now made (custom from Sheffield workshop) for 2.275mm OD tube – Can’t get a weld procedure to work yet. Power control has not been as good as previous software allowed. This supposedly fixed with recalibration – not tested. Have tried 5 electrode types, now altering tip angles. Main show stopper is weld head is only suitable for 3mm to 28mm OD – NOT 2.2mm!! This is causing havoc for RPM and arc gaps.

New weld head trials “ Borrowed” a Fronius weld head. Problems are this head has analogue encoder, M200 uses digital. Made a TTL to analogue conversion box. Made power plug conversion lead. Something unmentionable done to product ID. Weld head is a one-piece unit. It is very solid and the clamping mechanism gives significantly better alingment than the Swaglok product. Welds 1/8” equally well in 316L and CP2 Ti. Have to make some proper tests (NDT DT)as visual inspection not telling me anything. Will reference with previous welds from M H head combo. Dimensions are very similar to the smaller 4H weld head. This is significantly more robust and the encoder and power delivery system is significantly more advanced. Arc of clamping head could be a problem. 3x more expensive than 4H

Way forward 2 nd weld system procurement discussed at RAL on 13 th July. RF, TJ, JN, IW. – Tests will be made with a new 4H weld head and the M200 supply. Will this be any better for welding the small OD (2.275mm) Ti tube. – Test pieces have been sent to 3x orbital welding manufacturers. – Responses expected in Sept. – Procurement decision after evidence and testing.