Casting materials ASTM A148 vs. A487 3

[MrVance13]

I've read over these two standard and am not real sure of the differences in material requirement between the two. ASTM A487 is designated for Steel Castings Suitable for Pressure Service, ASTM A148 is Steel Castings, High Strength, for Structural Purposes. My question is, if I plan on using a casting for a hydraulic cylinder application is there a significant difference between the two materials required in these standards that I should consider.

Any help is appreciated.

 

[metengr]

Yes. You want the material specification for pressure service (A 487). Why? The basic reason is that the material specified in A 487 is applicable to pressure-retaining service as defined in the Scope statement.

Second, elongation (measure of ductility)is generally higher for the material grades in A 487 in comparison to the elongation values for the high strength steel castings in A 148. This is an important consideration for defect tolerance and leak tightness of castings under pressure versus using castings for strength purposes with no internal pressure.

 

[MrVance13]

I see, I considered ductility and for a material of 115/95ksi the R.O.A. was 30% and 35%, ASTM 148 and 487 respectively.

Ultimately the reason I asked is the foundry I've been working with has been providing castings using the 148 composition for some years (however, not to our spec)and I'm trying to figure out how much of a concern this should be. There's been years of field experience with 148 material to say its okay but just trying to make a for sure determination.

Thanks for your help.

 

[vanmorrison]

Great post! This topic is interesting to me.

I am interested in learning how the issue will be dispositioned and or reconciled considering the positive (I assume) service history.

I am interested in understanding how the manufacturer has been supplying non conforming material for many years and the condition has only just been discovered.

Are these cylinders to meet a ASME or a standard?

Are there any lesson’s to share?