welding issues in pressure parts
welding issues in pressure parts
(OP)
Hello, I am new in this forum. I have welding issues listed below. Is there any comment I will appreciate.
1. There are 5 weld passes to joint stub tube to header with materials of SA213-T12 and SA335-P12 in pressure parts of power plant. E8016 electrodes were used in the root pass, second pass and final pass. However the third and forth pass have E9016 electrodes instead. The temperature of preheat snd postweld heat treatment are 121C and 690C respectively. Are there any effect related to mechanical properity of the joint?
2. To tell E8016 and E9016 in weldment, PMI(positive material Identification) equipment was used to measure the surface chemical composition of final pass weld. Is there any experience of welding experts to do such a same thing in the world? Is there any recommendation to me how to tell different passes in weldment?
3. In lab, the weldment sample was taken through metallurgical analysis to show the microhardness of weldment as high as 350Hv. Is there any meanings for weldment?
1. There are 5 weld passes to joint stub tube to header with materials of SA213-T12 and SA335-P12 in pressure parts of power plant. E8016 electrodes were used in the root pass, second pass and final pass. However the third and forth pass have E9016 electrodes instead. The temperature of preheat snd postweld heat treatment are 121C and 690C respectively. Are there any effect related to mechanical properity of the joint?
2. To tell E8016 and E9016 in weldment, PMI(positive material Identification) equipment was used to measure the surface chemical composition of final pass weld. Is there any experience of welding experts to do such a same thing in the world? Is there any recommendation to me how to tell different passes in weldment?
3. In lab, the weldment sample was taken through metallurgical analysis to show the microhardness of weldment as high as 350Hv. Is there any meanings for weldment?





RE: welding issues in pressure parts
2. At this point, I would not waste time or money to locate the 90xx deposition. You can remove it by excavating to a depth where the welders switched electrodes. Again, I would qualify a WPS with what you performed in production and leave it alone.
3. The 90 series weld deposit is higher strength in comparison to the 80 series deposit and will have higher hardness. Even at 350 HV hardness for a boiler application, I would not worry. If anything, the weld region will temper in service.
RE: welding issues in pressure parts
Actually, stub tube leakage was occurred in hydrostatic test. May be cold crack was a reason to fail. In question 3, sample taken to show 350Hv is higher than I expected. The microhardness of weldment is usually ranged in 180-230Hv after PWHT. The parent material of SA213 T12 is about 180Hv. Does 350Hv mean inproper PWHT process in weldment and the reason of crack?
RE: welding issues in pressure parts
RE: welding issues in pressure parts
RE: welding issues in pressure parts
"Nobody expects the Spanish Inquisition!"
RE: welding issues in pressure parts
RE: welding issues in pressure parts
RE: welding issues in pressure parts
RE: welding issues in pressure parts
You are going to have some variability and surface preparation is critical. I would stay with the rebound tester and improve your test method (preparation and training). Keep in mind the variability could be the PWHT exposure range where the tempering was not fully achieved in certain locations due to temperature profiles. Again, the data should be reviewed by competent individuals.
RE: welding issues in pressure parts
RE: welding issues in pressure parts
RE: welding issues in pressure parts
RE: welding issues in pressure parts
Also I assume the electrodes were E8016-B2 and E9016-B3, which would require appropriate qualification.
RE: welding issues in pressure parts
RE: welding issues in pressure parts