https://app.aws.org/forum/forum.plAmerican Welding Society Forum - Metallurgy15 Latest forum posts2023-10-31T16:26:01ZmwForumhttps://app.aws.org/forum/topic_show.pl?pid=288945Steel manufacturer spec differs from ASME specqcrobert2023-10-31T16:16:07Z2023-10-31T16:23:39Z0https://app.aws.org/forum/topic_show.pl?pid=288450PWHTJim Hughes2021-06-02T10:54:19Z2021-06-02T19:15:45Z1https://app.aws.org/forum/topic_show.pl?pid=288393Filler Metal help needed8030562021-03-27T16:07:37Z2021-03-27T16:39:23Z4 The heat treatment of the "lot" may have been different from the typical shipments of steel received from the supplier. Perhaps a new supplier was used that used a different heat treatment or possibly the tweaked the chemistry in comparison to other shipments. Let's face it, purchasing agents are always looking for the "deal" that will save money. They don't always appreciate the repercussions of minor changes in chemistry or heat treatment.
Another possibility is the filler metal was exposed to the atmosphere long enough to absorb moisture, thus introduce hydrogen into the weld and HAZ. Think of FCAW electrode that has been left on the wire feeder over a long weekend in humid conditions. FEMA limits the time a spool can stay unprotected to 8-hours in a seismic region if I remember correctly.
Most truck frames of modern tractors are quenched and tempered. Generally the manufacturer will prohibit welding of any sort in behind the front spring hanger to the far back of the rear spring hanger. That area, between the front and back wheel sets see the highest stresses and Q&T steels are degraded whenever they are welded or subject to high temperature above the tempering temperature used by the manufacturer.
It would make sense that the trailer manufacturer would use similar materials for their trailer frames, i.e., maximize the mechanical properties and reduce weight so they can haul more product.
The material (Q&T steel) is very sensitive to hydrogen assisted cracking. I would expect the cracks to initiate in the HAZ of the weld to the Q&T frame. The WPS must be properly developed and followed to the "T". Slow cooling to ensure the HAZ isn't too hard and more sensitive to delayed cold cracking (hydrogen assisted cracking), but not so slow that the mechanical properties of the HAZ are substantially different than the expensive Q&T steel with the "great" mechanical properties. Designers often look at the mechanical properties and pick the highest strength because they can reduce the thickness and save weight. What they fail to appreciate is the difficulties those same steels bring to the table. And to the uninformed welder; steel is steel and it will rust if it isn't painted.
Al]]>
https://app.aws.org/forum/topic_show.pl?pid=288392Filler Metal help neededtoddler2021-03-27T13:28:03Z2021-03-27T13:28:03Z4 This is a very late reaction. But I need to satisfy my curiosity:
Question: How can I tell from the metal chemistry that the metal could be quenched and tempered?
Thanks for the further enlightenment]]>
https://app.aws.org/forum/topic_show.pl?pid=288217FCC, BCC, HCP????8030562021-01-30T18:56:59Z2021-01-30T18:56:59Z1 I differentiate between a rod burner that deposit consistent looking weld beads day in and day out and a welder that understands the difference between the different types of steels and other metals that he or she works with and how to weld them properly.
BCC metals are typically harder and stronger than FCC metals at the expense of ductility. FCC metals are softer, not as strong, but have better ductility than BCC metals. HCP metals generally have improved corrosion resistance in certain environments, but they tend to be brittle when loaded in compression.
There are several good books on basic metallurgy. A good book for introductory metallurgy (Materials Science and Engineering by Carter & Paul)) is available from ASM, Metals Park, Ohio. AWS also has a couple of good books, perhaps a little more advanced, one is Welding Metallurgy by George Linnert.
A production welder that welds the same thing day after day probably can get by without a working knowledge of metals. On the other hand, a welder involved with maintenance or working in a job shop will have an advantage if he has a good working knowledge of metallurgy.
Years ago, when I had my welding shop, many of the jobs that came in the door were because I had a reputation of being able to weld materials the other shops struggled with. The difference wasn't my ability to lay a good looking weld, the difference was I understood basic metallurgy and how the metals responded to heating and cooling. I knew when to use high preheat, when to limit interpass temperature, how to select a compatible filler metal.
Al
Al]]>
https://app.aws.org/forum/topic_show.pl?pid=288216Filler Metal help neededJim Hughes2021-01-29T16:33:53Z2021-01-29T16:33:53Z4https://app.aws.org/forum/topic_show.pl?pid=288215FCC, BCC, HCP????toddler2021-01-29T15:28:24Z2021-01-29T15:28:24Z1
how does it help in the welding profession? Any recommended reading material? Thank you.]]>
https://app.aws.org/forum/topic_show.pl?pid=288188Filler Metal help needed8030562021-01-10T17:40:48Z2021-01-10T17:40:48Z4 The manufacturer should be contacted and politely asked for their recommendations.
Al]]>
https://app.aws.org/forum/topic_show.pl?pid=288183Filler Metal help neededPawndave2021-01-08T16:58:50Z2021-01-08T16:58:50Z4 I have a client that is welding trunnions to log truck trailers, they have been having issues with the welds detaching from the base metal. After performing a chemistry test the results are below. They would like to still use these trunnions but arent sure what filler metal to use. They have been using an E71T-XX filler metal with no problems intil they received this batch. And recommendations would be great. Thanks
Any help would be greatly appreciated.]]>
https://app.aws.org/forum/topic_show.pl?pid=288090Possibilities of transvers weld crack8030562020-09-03T12:44:54Z2020-09-03T12:44:54Z1 Al]]>
https://app.aws.org/forum/topic_show.pl?pid=288089Possibilities of transvers weld crackDhrumil Chauhan2020-09-03T07:02:30Z2020-09-03T07:02:30Z1 We have observed transverse weld crack in saw welding in API 5L X70M material grade linepipe. In order to find potential cause for same we have carried out chemical analysis which shows higher amount of Cu content arround > 1%.
During etching we also observed blackness in particular cracked portion during microscopic analysis. More or less no phase changes observed.
Al]]>
https://app.aws.org/forum/topic_show.pl?pid=287782Phase DiagramsAtuuel2020-04-01T12:53:57Z2020-04-01T12:53:57Z1
Or any software that can help by putting chemical composition in that software.]]>
https://app.aws.org/forum/topic_show.pl?pid=287437Welding on Hardened 8620 Tool Steel, any suggestions?8030562019-12-27T23:28:10Z2019-12-27T23:28:10Z6 New welding jacket; small, new leather welding gloves; small, new grinding shield, new welding helmet, power cable from the entrance box, receptacles, miscellaneous. Boy, it gets expensive quick! It's like buying a computer. It turns out the computer (welding machine) is the inexpensive part.
Al ]]>
https://app.aws.org/forum/topic_show.pl?pid=287436Welding on Hardened 8620 Tool Steel, any suggestions?welderbrent2019-12-27T21:46:26Z2019-12-27T21:46:26Z6