What is ASTM A789?ASTM A789 is a Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service.
CategoryCorrosion-Resisting and Heat-Resisting Steels
ScopeThis specification covers grades of nominal wall thickness, stainless steel tubing for services requiring general corrosion resistance, with particular emphasis on resistance to stress corrosion cracking. These steels are susceptible to embrittlement if used for prolonged periods at elevated temperatures.
Ok let's start with ASTM A789 chemical composition.
Grade UNS S31803
Ni4.5 - 6.5
Cr21.0 - 23.0
Mo2.5 - 3.5
N0.08 - 0.20
Learn more about chemical composition.
Now it's the mechanical properties turn:
Grade UNS S3180365 ksi (450 MPa) min.
Learn more about what is yield strength.
Grade UNS S3180390 ksi (620 MPa) min.
Learn more about what is tensile strength.
Elongation (min.) 50 mm0.25.
Learn more about what is elongation.
Reduction of Area (min. %)Not Required.
Learn more about reduction of area.
Grade UNS S31803290 HBW or 30 HRC max.
Learn more about what is hardness.
Density7480 - 8000 kg/m3 (around 7.9 g/cm3 or 0.285 lb/in3).
Learn more about density.
Elastic Modulus180 GPa (26107 ksi) - 210GPa (30458 ksi).
Learn more about the Elastic Modulus.
Poisson's RatioUsually around 0.26 – 0.31.
Learn more about the poisson ratio.
Allowable StressDepends on the project (And its factor of safety).
Learn more about the what is allowable stress.
My Material's RankWhile engineers will often look for the cheapest material they can use, I took a different approach to material's selection to help newbie students.
I ranked materials according to their yield strengths and ASTM A789 currently ranks 32 in my yield strength index. This means there are other 31 materials that are more resistant.
Note: I've analysed 134 materials in order to create an yield strength index. Check my astm material's comparison post for more details.
ASTM ClassroomAre you having trouble understanding the basics of ASTM?
What is the difference between Code, Standard & Specification?
This video will walk you through:
CitationWhen you need to include a fact or piece of information in an assignment or essay you should also include where and how you found that piece of information.
That gives credibility to your paper and it is sometimes required in higher education.
To make your life (and citation) easier just copy & paste the information below into your assignment or essay:
Luz, Gelson. ASTM A789 Properties (Chem., Mech. & Rankings). Materials Blog. Gelsonluz.com. dd mmmm. yyyy. <URL>
Now replace dd, mmmm and yyyy with the day, month, and year you browsed this page. Also replace URL for the actual url of this page (The < and > stay, ok?). This citation format is based on MLA.
Other ReferencesA480/A480M Specification for General Requirements for
Flat-Rolled Stainless and Heat-Resisting Steel Plate,
Sheet, and Strip
A1016/A1016M Specification for General Requirements for
Ferritic Alloy Steel, Austenitic Alloy Steel, and Stainless
E527 Practice for Numbering Metals and Alloys in the
Unified Numbering System (UNS)