Recent content by EdStainless

One of the problems with alloys like 91 is that you can't judge the creep strength of the welds based just on looking at them. If you don't actually have data on the impact of weld repair (and re-PWHT) then caution is needed.

You first stop needs to be the Trademark office web site. You will likely find that your first 20 choices are already trademarked by someone.

Overlapping HAZs are a rats nest of issues. In some cases it doesn't matter. In some alloys a little more heat isn't a bit deal, you test and make sure that it is OK. But in alloys where there is precipitation it can be a nightmare. Precipitates will grow and coarsen and this can seriously...

So you also looked at the face of the notch to assure that there was no tearing or chatter?

Perhaps you can find a plastic that has toughness/hardness similar to cartilage to use for an assessment.

Any surface treatments? 17-4 will only get you in the low to mid 40's HRC. With tool steels you are dealing with mid-50's into the low 60's. What are you cutting?

Were the notches ground or broached? I loathe broached notches.

How about virtually none. https://nickelinstitute.org/media/1724/materialsforsalinewaterdesalinationandoilfieldbrinepumps_11004_.pdf Unless this is oxygen free (<5ppm) and cold I don't see plain cast iron lasting in the velocity and turbulence of a pump.

You might be able to use a Best tester with some special fixturing. but I am more with IR on this. Measuring load (torque) may be your best option. We had CNC lathes that had a carbon steel backing plate that was replaceable. After every few pieces there was a cut taken from the edge of the...

dgee, we used to have to mix a very corrosive chemical into a blend. We found a source for investment case Ni alloy mixers. I can't imagine how a coated unit would be effective.

I did a lot of batten overlay once upon a time. We welded solid strips of Ni alloy to the CS and then welded thin sheets of Ni alloy to the strips. What a PIA.

The best way to see this to put a fine grid onto a flat tensile sample. As you pull it your will see distortion of the grid at stress well below the Engineering Yield Stress. This is small localized yielding. As you get more yielding you will one area start to neck, and then that will slowly...

If they are the correct polymer my hunch is that the compounder changed some ingredients. Different fillers (maybe just different brands) or different curative chemcials. We used to have difficulty in hot water service because of issues like this. Viton should work and EPDM or silicone should...

In the Level III RT class then you learned how to calculate this. Why is non-NDT professional worried about this at all?

All of the methods have a place. But you have to be smart about it.