Mechanical Testing Direction

[tensilecvn]

Hi All
I am after peoples opinions regarding mechanical testing of metals, specifically with respect to "Transverse" direction. Obvioulsy this means accross the primary grain flow, but my question is, in longitudinally forged bar, both Tangential and Radial directions are across the grain flow, and can exhibit different characteristics. In the absence of any identified directions, ie C-R or R-L etc within a specification, which direction do most people assume to be the correct "Transverse"

Thanks in advance for any valuable input.

 

[TVP]

The typical nomenclature used in North America is longitudinal (L), short transverse (ST) and long transverse (LT). The ST direction is the most affected. Some industry standards specifically mention requirements such as ASTM A370, B209, etc. Here are two links that have some additional information:

https://www.nde-ed.org/EducationResources/CommunityCollege/Materials/Mechanical/Mechanical.htm

http://www.sae.org/works/committeeResources.do?resourceID=329704

 

[AndrewFinAustralia]

Hi,

You mention forging - in cold rolled steels, there is a strong texture in the steel and anisotropic properties and directionality is important. Our customers used to deep draw cans from the stock and it was something we had to consider as plant metallurgists.

Whilst the standard would specify a direction to allow for grain flow in forgings to allow for an inclusion or a stringer, hot forging produces equiaxed grains in modern steel with the current trend towards producing clean steel with little impurity. I used to work with cold worked steel strip, never had to worry about hot rolled properties other than "was it correct and uniform thickness into the mill and thoroughly clean".

I thought that the only source of anisotropy would be stringers/inclusions or pearlite banding in a modern forging, but I was wrong. The dog ears on the ends of the slab when rolled indicate the texture in hot rolling. I googled the paper below that may give you another test direction.

http://www.msm.cam.ac.uk/phase-trans/2012/X80_2.pdf

End of the day, however, I'd be using the correct standards - are they the ASTM ones linked above?

 

[tensilecvn]

Thanks for the replies so far, very informative. I am testing in acc with ASTM A370 on mainly on nickel alloy products per API 6A 718.

 

[Qual7Eng]

and i wonder why customers are asking directional testing for steel castings, realy you will have comments over this.