Yieild strength of cast iron
Yieild strength of cast iron
(OP)
Hi,
I would to know the yield strenght for various grades of gray CI.
I know people use 0.2%y , can someone indicate the values or indicate any website. This for an analysis project, using a software which requires yeid strength.
thanking you
san
I would to know the yield strenght for various grades of gray CI.
I know people use 0.2%y , can someone indicate the values or indicate any website. This for an analysis project, using a software which requires yeid strength.
thanking you
san





RE: Yieild strength of cast iron
RE: Yieild strength of cast iron
nick
RE: Yieild strength of cast iron
= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm
RE: Yieild strength of cast iron
The "0.2%y" is a reflection of the practice of using a yield point as defined by the applied stress at which the steel has plastically deformed 0.2%. Graphically, your run a tensile test (which starts at an initial stress/strain of 0 [stress units]/0%). Then you draw a line starting at an initial stress/strain of 0 [stress units]/0.2% that runs parallel to the stress strain curve's elastic line. Where the two lines intersect, you get your 0.2% off-set yield strength.
As far as links or tabulated data, I would recommend ASM International's metals handbooks in your local university library or a 'google' search of 'gray cat iron' will turn up something.
RE: Yieild strength of cast iron
I checked several sources and could not find any reportable yield strength for gray cast iron automotive classes SAE J431 or ASTM standard gray iron Class 20, 40, etc or ASTM A159.
I would suggest for your software to use either .80 * UTS as a value for the fictitious yield strength, if you are also required to input the gray iron UTS as separate but distinct values. Or assign YS=UTS for data inputs. Just curious, what is this software analysis for?
RE: Yieild strength of cast iron
It makes no sense to assign a value to a material that doesn't exhibit plastic deformation for any practical purpose.
RE: Yieild strength of cast iron
If the material does not exhibit any plastic deformation in a practical sense, then the yield strength is essentially equal to the tensile strength. That is, the material elastically deforms until it breaks, with no plastic deformation. Setting yield strength to zero would indicate that the material starts plastically deforming immediately upon loading.
RE: Yieild strength of cast iron
My argument is this: What is the point of assigning a value for something that for practical purpose does not exist?
Gray cast iron is a brittle material. It has zero yield strength in the same sense that there is no yield strength because it does not plastically deform.
There is elastic strain only, no plastic strain. There is only UTS to measure.
RE: Yieild strength of cast iron
At the same time, "Elongation of gray iron is very small, on the order of 0.6%".
I hadn't realized that the material was non-linear elastic, which makes yield strength meaningless, since it cannot be accurately measured (without risking damage to your extensometer if the material fails before you reach 0.2% elongation), as rnd2 indicates.