PMI Training Resources
Alloy Quick Reference and Chemistry Guide
These resources are here for people to begin (or continue) learning some common alloy specifications. One of these documents is simply a quick reference, mainly for XRF, and the other is populated with a more in-depth list of specs as published in the Unified Numbering System, including all relevant elements.
CLICK HERE TO DOWNLOAD XRF QUICK REFERENCE
CLICK HERE TO DOWNLOAD ALLOY CHEMISTRY GUIDE
Now…that said…these are a tool, and they’re one of many. We have to be careful not to only see nails because all we have is a hammer. The world is a big place, full of lots of new and different things. Many of those new and different things aren’t on these sheets. Ultimately, the PMI tech is responsible for knowing the environment and what alloys may be in play there. I’ve selected the alloys in these pages because they show up time and time again across multiple applications. I would consider these to be living documents, and the content may change with usage patterns in various industries.
Alloy Practice Sheets
The concept behind these refresher sheets is one of "use it or lose it." It's not meant to be difficult or tricky, but to simply keep some pathways in the brain alive until the next job comes up. There are plenty of cross-trained PMI techs out there who spend the majority of their time on other NDT methods, only picking up a PMI instrument on occasion. In my experience, that tech will make better decisions if they aren't scrambling to remember what basic alloys look like. Modern instrumentation does extremely well identifying clean and well-prepped material, but beautiful surface conditions aren't always easy to come by (anyone who's done a rope-access retro PMI survey knows what I mean). Tramp elements from slight surface contamination can cause an incorrect ID, but it won't fool a human operator if they know what they're looking for. That's where these practice sheets come in. They'll keep the brain up-to-date on what common alloys look like so you'll know what should and shouldn't be there at a glance. The point isn't to become a walking alloy knowledge repository, but to know enough to not be forced into putting blind faith in the instrumentation.
If you're in a supervisory role, consider posting a new sheet weekly on a bulletin board, send it in an email, or even text it to your people. Spread it around. Get yourself and your employees thinking about these common alloys in the down time. You'll see more success and less mistakes on those emergency, middle-of-the-night-shift calls.
If you're a tech, strive to get them all right, every time. Try to remember additional things about each alloy, e.g., types of service, general specs, welding filler metals used, etc. Discuss them with your coworkers and quiz each other.
The data we’re focusing on is from XRF shots on some of the most common alloys out there:
304
316
321
347
410
1.25 Cr .5 Mo (F11)
2.25 Cr 1 Mo (F22)
5 Cr .5 Mo (F5)
9 Cr 1 Mo (F9)
91 Chrome (F91).