TWI Industrial Member Report Summary 64/1978
By J Honeycombe and T G Gooch
Background
Stress corrosion testing of welded joints in one fully ferritic and three ferritic-austenitic steels has been carried out. A range of welding processes was employed, with matching composition, austenitic stainless steel, and nickelbase consumables. Testing was conducted in MgCl2 and CaCl2 solutions at 155º degrees and 130º degrees respectively, with exposure periods of up to 500hr.
Failure of welds in the duplex steels took place in parent material, heat affected zones, and weld metals, with no major propensity for failure in any specific weld area. In all instances SCC occurred only at stresses similar to the threshold stress of the relevant parent material.
Parent material failure of the ferritic steel in CaCl2 was observed, but no cracking was found in the welds examined.
The results obtained indicate that welding had no significant adverse effect on the stress corrosion resistance of the materials examined, at least under the test conditions employed.