Can ASTM A1018 be substituted for A529 or A572? 4

[waytsh]

Hello,

Does anyone know if A1018 steel can be substituted for A529 or A527? I have a customer who has begun fabrication on a project using some A1018 steel and the specifications called for A529. The Army Corps of Engineers wrote the specification and my customer is worried about the fabricated columns being rejected. any help would be appreciated.

 

[metengr]

waytsh;
ASTM A 527 was withdrawn in 1994 and replaced with A 653. ASTM A 529 is for High Strength, C-Mn steel of Structural Quality.

The answer to your post is this, I would not permit substitution of 1018 steel for either specification. Why?

The carbon content is too low in 1018 to meet the minimum tensile requirements for A 529. For steel used in A 653, the maximum carbon content permitted is only 0.15% by mass for certain types and for other types permitted you need micro-alloying elements added, which is not the case for 1018.

You would be wise to stick with what was specified!

 

[metman]

waytsh,

I think you are mixing SAE/AISI designations with ASTM designations. Maybe you are not a resident of the USA and do no understand the difference.

In any event, your customer cannot make this substitution without prior approval from their customer and their customer is not going to allow this substition especially if it is the US Army.

ASTM A1018 is sheet material whereas the specified material of ASTM A529 is as follows (not sheet)

ASTM A529 / A529M - 05(2009) Standard Specification for High-Strength Carbon-Manganese Steel of Structural Quality

1.1 This specification covers carbon-manganese steel shapes, plates, and bars of structural quality for use in riveted, bolted, or welded construction of buildings and for general structural purposes.

1.2 Material under this specification is available in two grades:
Grade Yield Strength,
ksi [MPa] Thickness
50 [345] 50 [345] Plates to 1 in. [25 mm] thick
to 15 in. [380 mm] wide
Bars to 3½ in. [90 mm]
Shapes with flange or leg thickness to
1½ in. [40 mm] inclusive
55 [380] 55 [380] Plates to 1 in. [25 mm] thick
to 15 in. [380 mm] wide
Bars to 3 in. [75 mm]
Shapes with flange or leg thickness to
1½ in. [40 mm] inclusive

Your customer must have started using SAE/AISI C1018 which is not sheet and more comparable in geomnetry e.g. bar, plate, tubing, etc but the mechanical properties are much below that of A529 grade 55 or grade 50. C1018 has a YS of only 32ksi whereas A529 has YS of 50Ksi as noted above.

If you do not know the following abbreviations, post it here and we will spell it out for you: ASTM, SAE, AISI, YS.

 

[TVP]

Can you clarify if it is ASTM A 1018, or grade 1018 (UNS G101800)? ASTM A 1018 covers heavy thickness coils in a number of different grades, which may be suitable as an alternative to A 529.

 

[metman]

TVP,
I guess you are saying that if the customer requirement is tubing, it could be rolled from ASTM A1018?

 

[waytsh]

Sorry for not being clear. I am refering to ASTM designations. Here is the link to the standard I am looking at for ASTM A1018:

http://www.astm.org/Standards/A1018.htm

To clarify further I am also referring to ASTM A572 and ASTM A529. From what I understand the mill certs specify that the yield of the 1018 ranges from 58 to 60 ksi which exceeds the required yield of 50 ksi specified. According to my customer the steel suppliers have assured him that it is an acceptable susbstitute but he still wanted to make very certain because he does not want to finish fabrication on the columns just to have it rejected.

Thank you all for the rapid response.

 

[ajh1]

A1018 is a coil only spec. The ASTM standards are clear that if it is to be decoiled and cut to length as we would do for webs, it must be tested per ASTM A6 before it can be deemed a “plate” material. This testing requires the decoiler to test yield/tensile/elongation at the outside of the coil and then again at a point approximately half way through the coil. Based on these tests he may then recertify the material from A1018 into an appropriate plate grade, in this case typically A572 Grade 55. While there is an SS grade available in A1018, there really isn’t any equivalent plate standard that can be used. A529 is restricted to plates only up to 15” wide. A1018 coil is generally much wider than that. It is difficult to prove you can obtain consistent yield at the 50 ksi levels you are looking for in the wider coils, hence there has never been a wide plate spec in an SS type material. This is an issue of differential cooling within the coil during original rolling.
If for some reason a manufacturing process used the coil directly, in theory at least you wouldn’t have to go through the testing and reclassification routine. Mechanical properties-wise there is minimal defined difference between A1018 grades and the equivalent A529 or A572 grades.

 

[waytsh]

Thank you ajh1, this is very helpful. Seeing as how it is not coiled I assume this is why ASTM A1011, commonly used as web material in metal buildings, does not require testing per ASTM A6 as can be used "as is". So once again if ASTM A1018 were to be used in place of ASTM A1011 as web material it would have to be recertified as you described above.