410 ss 1

[weldtek]

What are the chances of hot rolled plate, type 410 SS meeting impacts 35/40 @ -20F if first performing a Q & T treatment. No special chemistry controls were specified and just by memory I think the P was at .026. S .015.
If a heat treatment would likely work what would you suggest for a tempering temp. PWHT will be at 1400F for 1 hour.
Thanks,

 

[metengr]

weldtek;
You are probably not going to like what I recommend, but your best bet is to conduct actual impact tests, if you have enough material. They are relatively inexpensive tests and you or anybody else cannot dispute the data.

Regarding post fabrication heat treatment, the temper needs to be selected based on your strength requirements. Also, make sure that you avoid lowering the impact properties from tempered martensite embrittlement (around 650-1000 deg F).

 

[QAFitz]

Weldtek,
From a "gut feel" it looks like your PWHT temp is going to be your tempering temp. Any lower than that would negate the tempering. Do you have other strength requirements like Tensile/Yeild/Elong etc. ?
By the way, 35/40 what, Ft.Lbs or Mills Lateral Expansion
(MLE) ?

 

[weldtek]

Thanks for your input. Apparently, there's limited availability of type 410 and the only thing we could locate was hot rolled. We have to meet 40/35 ft lbs at -20 F and we have to PWHT for an hour at 1400 F. So, I had suggested we purchase a piece of this plate, put it through the
Q & T, and PWHT cycle and perform the mechanical tests. I just wonderded if this has any chance of meeting our requirements.
thanks,

 

[metengr]

weldtek;
Agreed. If the 410 ss has a lower end carbon content, and is Q&T (temper at 1450 deg F for peak toughness) followed by PWHT at 1400 deg F to avoid disturbing the original temper it probably should make your impact requirements.

 

[stanweld]

If you are welding this with matching chemistry filler metals, I doubt that you will achieve these values in either the deposited weld metal or the HAZ. Good luck.

 

[redpicker]

Just out of curiosity, what are the dimensions of the plate. If you try to (liquid) quench don't be too surprised to find cracks. 410 will crack very easily.

If I had to heat treat 410 that had an aspect ratio over 2.5 or so, I think I'd air cool it. If Impact Testing was required, I'd look into forced air cooling (fans). In fact, I think I'd have to prove that I couldn't achieve adequate properties with air cooling before I'd try to use a liquid quench. I've busted way too many parts made from 410.

By the same token, I'd be nervous about welding on it, too.

rp

 

[GRoberts]

I highly doubt that what you are trying to achieve is possible (especially with matching filler). Our only previous tests are at 70F with 28/30/25 ft-lb in HAZ and 21/29/21 ft-lb in weld. PWHT was 1275F for 8 hours with fan cool. We would even have trouble using 410NiMo filler. After a lot of trial and error, with E410nimo FCAW wire, we finally achieved 50 ft-lb at 0F. For filler you might have to look at inconel. Not sure what you will do with the HAZ though. Any chance you can use 415 instead?

 

[metengr]

GRoberts;
Your PWHT temperature at 1275 deg F for this material is about right for your stated impact values. At 1400-1450 deg F, the data I have seen for 410 ss Q&T base metal puts you very close to 50 ft-lbs at -25 deg F. Again, the carbon content and PWHT or tempering temperature are two of the primary drivers that will either increase or decrease the 50 ft-lbs band. If the GTAW process is used to maintain grain refinement in the base metal HAZ, this will help. Either way, it will be a close call and impact testing is required.

 

[weldtek]

Thanks all, for the helpful input. We are working with our client to see if there is a possibility to relax the impact requirements, but, if not, I have certainly been given some good advice.