There are a few times when I am just on, ya know? Maybe it’s the 32 ounce RTIC cup that my gal Audra (shout out to that Georgia girl in Philly now!) gave to me for Christmas so that I have a continuous hug in a mug (aka coffee), perhaps the mutli vitamin that I take daily (could it possibly be), or slight chance that it’s my Spotify playlist of baller jam playing just loudly enough for me to get the good mojo going when I hear Korn’s cover of “Word Up”.
Who knows? It happens, tho.
On this particular day, while listening ever so intently on a conference call from hell of excess inventory and what can be done about it, I spoke.
Those that know me, know I speak a lot. I mean, a lot. I’m a chatty kinda gal, silence makes me uncomfortable — much like too much white space on a paper. Like, it needs to be filled. Shockingly enough tho, I have learned on conference calls and most meetings, I need to just STFU and listen.
But this time, I just couldn’t.
Next thing, I know, while the discussion is about small diameter 17-4 H1150 (what I have always known to be SH (Single H) 1150 as in not DH (Double H) 1150, I pipe up like I have something important to say.
So I said, “I can see what we can do here in the Southwest with it as many times, SH1150 will meet DH1150 properties (the mechanical testing parts — yield, hardness, etc), IF the requirement is to meet properties and not the double heat treating.”
What? Who said that? Oh dayum. I spoke in a call when I should have just been noting the activity of next steps. Next steps? Whose steppin’? Well, that would be me, when it’s all over and the fat lady starts up the pipes.
But yep, Folks. It can happen. And it does. More than you’d think.
So why is 17-4 both single aged and double aged?
Well, to get the technical of it, I had to burn a call to my go to guys at 10.5% Guroos again. (One day, I’ll ask for permissions to use their names, they are great folks there and they help me daily. I mean DAILY.)
The standards for aged hardened material is none other than our buddies, good ol’ ASTM A564, AMS 5643 Mod, Condition H1150.
Notice I just mentioned SH1150. Not DH1150.
In our oil and gas world, we live by the standard NACE MRO 1795. NACE doesn’t even MENTION SH1150. Distant relative. Double H, Folks. Because more has to be better, I guess.
NACE is the National Association of Corrosive Engineers. The big think tank of folks way smarter than I that have been looking at corrosive properties of materials and having fun doing it. These cats sit around in chat rooms several times a year, talking about things like resistance to corrosion, useful life spans of the tooling, and oh mah gah, risk mitigation from tool failure (shudder!).
Back to DH (Double H)1150.
Well, heat treating a bar of 17-4 twice will give a bar higher strength and make the material harder, because not only is more better- the twice heat treated bar will be more resistant to a corrosive environment, have a longer useful life in the tooling and will be more resistant to failure in end use application.
To get there tho, its a very tight timeline thru a flaming hot. big ass oven.
When material gets treated, it actually gets softer. No shit. It does.
Tensile is lowered because the heat treating temps are in lower ranges and the second aging is at the freaking lowest temperature possible to obtain the desired results of –
Yep. Single H properties in a Double H bar.
My go to Guys at 10.5% Guroos (nope, I’ve not asked for permissions to use names yet– yes, I should have priorities in order) have advised me that temp ranges are sorta like suggestions — as in, “Get it this hot, don’t go over, because if ya do”,… Well, you just won yourself a fairly expensive do over, ya know whaddaimean?
Here’s the mechanical deets, Peeps!
|Ten(Min)||Yield (min)||Elongation||Reduction of Area||Harndness (HRC)||Impact (ft lbs)|
|DH1150||125||105||16||50||24 Min / 33 MAX||30|
Remember tho —
NACE is applicable to DH1150, Double H 1150 or even H1150D. To be in compliance completely with NACE, the material does have to go thru the second aging. In the check list world of receiving — that second aging has to be on that MTR. If not, it’s a reject. There are material requirements that don’t require he second aging. One just has to read the requirement to the MTR and ask the question — Do you want properties or the extra heat?
I leave you with this — “A grill is just a source of heat. Just like a stove, it is very user-friendly.” Bobby Flay