Stainless steel or Chrome molly

[Bill Rodolph]

Bluing is an oxidation process. Stainless was made to resist oxidation, therefore, much more difficult to blue. There are chemicals that will do it, but it's not as deep nor does it look near as good. Carbon steel blues much better. As mentioned before, Winchester plated their stainless before bluing, but I believe it was an iron plate, not copper.
As far as barrel life, I have heard it both ways for as long as I can remember, so whatever you want to believe is true! I remember the cold temp debate, it seems a factory stainless barrel came apart on an Alaskan hunt. It was attributed to a difference in "notch toughness" a test that is done on steel, but now I don't remember the specifics of notch toughness, sorry, maybe a metallurgist could weigh in about now.
I have cut an awful lot of chambers and threads and I personally believe that stainless machines a little better, the chrome moly seems to be tougher to me and has hard spots in it.
My two cents.

 

[MikeT49]

[QUOTE="Bill Rodolph, post: 37772158, member: 1317418" It was attributed to a difference in "notch toughness" a test that is done on steel, but now I don't remember the specifics of notch toughness, sorry, maybe a metallurgist could weigh in about ....[/QUOTE]

Dang that knocked a few cobwebs loose. Thanks. The old Charpy V Notch test. College Physics class, engineering school, 1967. Tests relative yield strength of materials. We actually had to use our brain and a slide rule to crunch the numbers.

 

[carlsbad]

Charpy v-notch test is used to measure temperature transition to "nil-ductility". some steels will transition to a brittle state at low temperatures. Some at room temperatures. Some only at cryogenic temperatures. Nuclear Reactor Pressure vessels are tested every few years with charpy specimens sealed inside special compartments in the reactor to measure the effects of neutron embrittlement on the vessel steel nil ductility transition temperature to ensure the vessel isn't pressurized below that temperature. It is a very expensive process.

Of course since barrel steels are proprietary blends, we have to take the barrel manufacturers' word for the transition temperature. They probably don't have very good data, as this testing is expensive. since brittle fracture of a rifle chamber 4" from your nose would be a bad thing, I can see why they would be conservative.

--Jerry

 

[Dusty Stevens]

Charpy v-notch test is used to measure temperature transition to "nil-ductility". some steels will transition to a brittle state at low temperatures. Some at room temperatures. Some only at cryogenic temperatures. Nuclear Reactor Pressure vessels are tested every few years with charpy specimens sealed inside special compartments in the reactor to measure the effects of neutron embrittlement on the vessel steel nil ductility transition temperature to ensure the vessel isn't pressurized below that temperature. It is a very expensive process.

Of course since barrel steels are proprietary blends, we have to take the barrel manufacturers' word for the transition temperature. They probably don't have very good data, as this testing is expensive. since brittle fracture of a rifle chamber 4" from your nose would be a bad thing, I can see why they would be conservative.

--Jerry

Got a pic for you last week- maybe the week before. We had a bad storm roll thru and i lost track of time

 

[carlsbad]

Nice. Is that ANO?

 

[Dusty Stevens]

Nice. Is that ANO?

Yes. Just refueled both units

 

[MikeT49]

The reactors I have been involved in refueling are a little smaller. They fit in boats and as any good submariner knows "targets" (carriers). Did six years in uncle sam's canoe club, and 36 years working on them as a civilian at PSNS. I bet you guys know what BFPL means.

 

[carlsbad]

Brittle Fracture Pressure Limit?

In civilian reactors we use the have a graph with acceptable pressures and we can't even put the head on below the NDT temp (Nil-Ductility Transition Temperature).

 

[MikeT49]

Might have had a career in civilian nuclear power if it wasn't for TMI. Gave the tree huggers somewhat exaggerated ammo to curtail expansion of the nuclear power industry.
Do you use BFPL gear in the civilian reactor world? Relief valves, temp alarms, etc?
I saw a show on Discovery Science about a very sharp lady engineer who was working on a solution to the waste problem. She was developing a way to somehow recycle what would be waste into usable fuel. Anything new on that front?

 

[Dusty Stevens]

Might have had a career in civilian nuclear power if it wasn't for TMI. Gave the tree huggers somewhat exaggerated ammo to curtail expansion of the nuclear power industry.
Do you use BFPL gear in the civilian reactor world? Relief valves, temp alarms, etc?
I saw a show on Discovery Science about a very sharp lady engineer who was working on a solution to the waste problem. She was developing a way to somehow recycle what would be waste into usable fuel. Anything new on that front?

The plants ive worked at have so much spent fuel on site she would have a field day. Im talking hundreds of casks in dry storage. Just finished a new pad for more casks about 5 acres big this month here in arkansas

 

[MikeT49]

The plants ive worked at have so much spent fuel on site she would have a field day. Im talking hundreds of casks in dry storage. Just finished a new pad for more casks about 5 acres big this month here in arkansas

What happened to putting the bad shit deep into salt mines IIRC in Arizona? Tree huggers again? Maybe somebody should suggest to the tree huggers that the only way to electric cars is nuclear power.

 

[carlsbad]

It was Nevada. It wasn't tree huggers so much as politicians: Obama shutting it down as a favor to Reed. Most people don't realize that electric cars, due to losses in the electircal process from generation to use, result in more CO2 than gasoline cars. You were smarter than me with TMI. I thought it would create a temporary blip and there would be a huge demand for Nuclear Engineers. I was right short term and received multiple good offers getting out of grad school. But since then nuclear has been a shrinking industry rather than growth. Dry fuel storage and decomissioning are current growth areas.

 

[bobm]

New Mexico ?


https://www.wipp.energy.gov/

 

[carlsbad]

WIPP accepts government waste only.

 

[butchlambert]

Back to the SS to CM debate. The cold weather thing with SS was Sako stainless barrels coming apart. Some barrel people quit offering light contour SS barrel blanks. CYA

 

[carlsbad]

Butch,
Good to hear. I always wondered what the failure(s) was/were that caused the concern. Like I say, the transition temperature can vary with minor changes in the metallurgy. And while charpy testing of each heat (batch) of steel is practical for large scale industrial applications, it isn't for every batch of barrel steel received from the mill. Companies had to make CYA decisions.

Sako's do originate in the land of hot days being 40 deg (F).

 

[JMA]

Seeing that 416 ss has a thermal conductivity rate of 24.9 and 4130 cm 42.7
Would a CM barrel be better in a sustained rapid fire situation due to being able to transter heat from the bore faster?

 

[Dusty Stevens]

Seeing that 416 ss has a thermal conductivity rate of 24.9 and 4130 cm 42.7
Would a CM barrel be better in a sustained rapid fire situation due to being able to transter heat from the bore faster?

Yes but dont tell anybody- they’re inferior you know?

 

[MikeT49]

Has HY-80 or HY-100 ever been utilized for barrel steel? Or is it better suited for razor blades? I saw a lot of submarines get cut up, tons of HY-80 and HY-100 shipped out for scrap.

 

[Papa Charlie]

Seeing that 416 ss has a thermal conductivity rate of 24.9 and 4130 cm 42.7
Would a CM barrel be better in a sustained rapid fire situation due to being able to transter heat from the bore faster?

That also means that CM will heat up faster than 416 as it is conducting the heat from the discharge that much faster throughout the barrel.