Easy question on ASTM A 36 4

[blacksmith37]

I am retired and discarded all my ASTM specification books as they were obsolete. Long ago I was on most of the steel (A) committees. Recently someone told me the current ASTM A36 (19) specifies yield as "yield point" not "yield strength" ( offset 0.2 % offset ). I can't believe they would use yield point ; am I getting senile ?

 

[mfgenggear]

ya let's see what the experts have to say on this one. I am an old timer as well, I known it as yield & ultimate tensile strength.

 

[EdStainless]

Considering that the value that we report as Yield is an engineering construct and has no real existence we can call it whatever we want to.
Many high ductility metals (austenitic stainless steel) show no straight portion of a tensile curve.
I don't have -19 handy, but I do have some other steel A specs that are -19 and -20 revs and they all still say 'Yield Strength at 0.2% offset'.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[mfgenggear]

I was reviewing that the other day and looking at how the yield strength was derived, and the percentage of elongation.

 

[SJones]

The 2019 version does indeed use the terminology "yield point." It is assumed that subclause 11.7 of ASTM A6 would then kick in to assist with any discussion as to which determination methodology to use.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[ulyssess]

The oldest edition of ASTM A36 I own is 00a. In this edition and all of the following it was “yield point”. Also other structural steels like A283 or A572 define “yield point”. Reading ASTM A6 par. 11.7 it is clear that “yield point” is the general rule. Only for extra high-strength quenched and tempered steels in ASTM A514 “yield strength” is defined as these steels probably never show a yield point.

 

[blacksmith37]

I guess there is always something to learn ; I was wrong about using yield point in a spec. Part of my excuse is that I worked primarily with API materials my last 15 years and never remember a steel with a yield point. The line pipe was pretty much Nb micro alloy 60+ yield or casing and tubing with 55 min yield and mostly 95 min yield. And Q & T Cr; Mo wellhead. Thanks for setting me straight.

 

[mfgenggear]

I rarely work with ASTM A36 more with AMS specifications, which do not use yield point but instead UTS, & YTS

 

I've got a better suggestion for ASTM: make A36 obsolete.
I am tired of asking designers to substitute A516-70 plate for A36 plate.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[ulyssess]

"make A36 obsolete" ?
A 36 does not cover only plates, but also shapes and bars. ASTM A36 refers to ASTM A6 for a lot of general conditions. ASTM A6 contains a lot of tables for dimensional tolerances, mainly for shapes. If A36 is replaced by a pressure vessel standard then all this is missing.
I do not know the US construction code ASCE. The corresponding European code contains a lot of rules and data concerning fatigue, brittle fracture etc. These data are related to the specific steel grades contained in EN-standards for construction materials. For other materials like pressure vessel steels, you will not find corresponding rules and data and this is therefore an obstacle to the designer of a construction.

 

[mfgenggear]

in gear fabrication UTS & YTS is standard for design

 

ulyssess [sic]

Did I mention anything about pressure vessels?
I am well aware that A36 covers a wide variety of forms and that it is still widely used.
The 'general conditions' you mention are the only places A36 is fit for purpose. If the strength were any lower it would make sense to drop tensile requirements altogether. And forget about impact properties for this stuff.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[david339933]

Did I mention anything about pressure vessels?

Well kinda....SA-516-70 is Carbon Steel for Boilers and Pressure Vessels.

 

Can be used anywhere plate is used. It is listed in CSA W59 and I believe AWS D1.1.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[david339933]

It is also triple the price.

 

Really?

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[weldstan]

Fifty years ago, we downgrded heats to A-36 and if the downgrade wouldn't meet A-36 it was downgraded to fence post and if it couldn't meet fence post then scrapped for remelt. With a slight hammer tap, I've fractured a 1/2" thick A36 angle 8" long in Florida where the steel temp was over 100F. It did have a 1/16" crack induced by a small tackweld to attach a part number. So one must simply beware on the servicee conditions and the need for more controlled chemistry to prevent failure. A-36 can be purchased with quite good mechanical properties. Buyer beware.

 

'fence post quality' is how I think about A36. Only to be used in frost-free states.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[blacksmith37]

A 36 can be anything , it is only guaranteed to be steel . Once a refinery needed some plate fast for a repair . The only "off the shelf" was marked A 36. We we did tensile , Charpy and inclusion /surveys ( we needed resistance to hydrogen blistering). It was about the best carbon steel we had seen ; guessed it was leftovers from some critical application.

 

You got very lucky, blacksmith37

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."