Welding and Braze Evaluation
Members of our team have industrial experience in welding related to submerged arc, MIG, TIG, electron beam, laser, electroslag, and metal arc welding.
We do both failure analysis and first article testing. We have experience with materials ranging from carbon steels, stainless steels and aluminum, to titanium zirconium and tantalum.
We also have extensive experience with polymer welding.
Examples of Case studies:
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316L Stainless Steel welding procedure development with the aid of metallographic sectioning.
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Incorrect weld repair of centrifugally cast piping for reformer furnaces.
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Failure of electron beam-weld due to pure weld preparation.
Example One
PROCEDURAL WELDS WITH LOW DELTA FERRITE ROOT RUNS IN TYPE 316L STAINLESS STILL
These welds were made to qualify the procedures necessary to obtain root runs with a high resistance to delta ferrite corrosion. The root runs are almost pure austenite for good corrosion resistance while the succeeding runs contain delta ferrite for adequate hot cracking resistance of the massive centre section of the weld.
Weld made with J preparation. One run TIG with low ferrite filler wire. Succeeding runs with higher ferrite using manual metal arc. x25
Weld made with J preparation. Three runs TIG with low ferrite filler wire. Succeeding runs with higher ferrite using manual metal arc. x25
Selective corrosion of delta ferrite containing areas.
x200
Selective corrosion of delta ferrite containing areas.
x200
Example Two
HK 40 CENTRIFUGALLY CAST REFORMER TUBING INCORRECTLY REPAIRED BY WELDING
Extensive interdendritic bore porosity was repaired by welding. Weld repair is generally very difficult with this type of defect and is not recommended. It is far better to cut back tube until sound metal is found and then make use of the shorter but sound section.
Section of tube showing area which had been ground after weld repair.
Weld repair of interdendritic bore porosity. The porous areas had not been removed completely and cracking had occurred at the interface between base metal and weld.
