I would appreciate if anyone could clarify something in QW420.2 for me. The statement I'm questioning (1st sentence, 2nd paragraph) is:
"...welding procedure qualification with a base metal in one P-Number (or P-Number plus Group Number) or one S-Number (or S-Number plus Group Number)...
Alfa Laval does make disc stack centrifuges from 2205. We use their centrifuges (different application - sand/water/oil slurry) and have not had cracking problems in the past. Ours are older models however and are made from 329 Duplex - 2205 is an improvement on that (especially if you do any...
Thank you everyone for your help with this. I was confident that the reamer broke because it was placed under loading conditions for which it was not designed. However, I wanted to discount the possibility that it was a flawed bit so I could hammer the point home that we shouldn't be modifying...
I don't have an unused reamer to compare this one two as we can't figure out who supplied us with it and can't find any others that are the same as this one in the tool crib. The reamer is a helical tapered pin reamer and is 12" in total length. It has left hand helical flutes for an...
Thanks for the response. Our company policy is that tools should not be modified but obviously this is not being enforced.
I'm pretty sure the chem. analysis is good as we did a quick PMI with a nuclear analyzer to confirm the results of the spark test and the results matched. I'll have a...
Unclesyd - I hear ya on the lack of common sense on this tool mod. I realize the whole cause of failure seems incredibly cut and dry. It's just hard to convince people that this is such a bad practice because they've been modifying these reamers to use them with impact guns in the field for...
Unclesyd - Using wet flourescent MPI I did find one other small crack at the tip of a spline coming from the fracture face. I'm having the area mounted right now so I can take a better look. One other area away from the fracture face was mounted and I haven't had a chance to examine the...
I'm analyzing a reamer bit that failed in in a spiral path, with a flat fracture face, in a brittle manner. I cannot identify the manufacturer of the bit (the only markings are HSS Poland) and consequently have no mill certs for the chemistry to check the material against. I sparked the reamer...
I have a component that is spec'ed as 304 SS. However, it was brought to my attention that it is magnetic so I had PMI done to confirm that it is 304. The chemistry checks out. How is is possible for an austenitic to be magnetic??
Thanks everyone's help so far - I recommended to the mechanical engineer that we try to use bronze bolts. I'm waiting to hear back regarding the strength requirements for the bolts to see if/what bronze fasteners might be acceptable. If we can't go with bronze, I think the stainless types TVP...
The bolts will definitely get wet. The water isn't pure. It can have a chloride content of up to about 720 ppm (pH is also around 9.7 for what that's worth).
I believe the thought was to go for stainless bolts out of convenience but I can look into it and see if we can get some bronze bolts...
I have been asked if stainless steel bolts can be used to fasten together a two part C937 Bronze (80%Cu, 10%Pb, 10%Sn) sealing ring without risking galvanic corrosion (water (80 deg C) on one side, hydrocarbon vapour on the other side). I've tried to consult the galvanic serious but find myself...
GGH - I have a book you should definitely check out. I took Materials Engineering and think this is probably the best text I bought in University and it has been really helpful now that I am in industry. The book is called "Structure and Properties of Engineering Alloys" by William...
That makes sense. I've been trying to find a TTT curve but haven't come up with one yet. You're right - it's hard to find any info on this material except for references to the general tune of "new duplex materials are far superior to the original duplex alloys like 329". Thanks for...
I have a 1.5" thick piece of equipment made of 329 Duplex (old duplex grade, approximately 70% ferrite). We experience metal loss in isolated areas (cutting due to slurry) and weld repair these areas. The manufacturer does not recommend weld repairing the material more than 3 times, as...
I have damaged inner and outer races from a roller bearing that show discoloration (bluish and red/orange)markings parallel with the roller axis. I believe the discoloration may be due to corrosion but I'm really not sure. Is there anyone out there that I could send a photo of the bearing to...
