Hello,
My first attempt at qualifying a new WPS for welding 1.25 Cr -.5 Mo steel "almost passed". Both root bends passed, but one face bend did not quite pass. I am awaiting the bent specimens from the lab. Here is a description of my first process attempt:
1/4" Thick ASTM A387 Grade 11 Class 1 PVQ plate, with millscale thoroughly ground off of top & bottom sides of beveled ends
.035" ER80S-B2 in Short-Arc Mode using C-25 Gas at 35 CFH
250F Preheat & 1275F Postheat for 1-1/2 hours (& also left in furnace to cool down to RT)
Pass #1: 21 -22 V & 150A. Travel Speed 15 ipm. (.125" gap a bottom of groove w/backing plate)
Pass #2: 22V & 150A. Travel Speed: 11.25 ipm
Pass #3: 22V & 140-150A, 7 ipm (each pass was ground prior to welding the next pass)
Wire feed rate was 276 ipm.
Now the wire manufacturer suggests cutting amps down by 10 -15 amps and/or? switching to either Ar/2%CO2 or Ar/5%CO2. So my new concerns are:
1. I should have researched this type of base material more thoroughly, as it appears the preheat should have been 300F minimum. Is the 250F preheat the most likely variable that caused the single face-bend to not pass & I just need to change that one variable?
2. If a gas change is highly recommended - which one of the 2 mentioned above should I try next - or is there a better one. I am wondering about 50 Ar/50 CO2?
BTW - we routinely butt-weld carbon steel and stainless pipe fittings using ASMW qualified Short-Arc procedures, so we prefer this transfer method. Thanks in advance for any suggestions.
ASME Qualification for GMAW-S Welding of ASME P4 G1
Re: ASME Qualification for GMAW-S Welding of ASME P4 G1
