Nondestructive test to determine Fy of steel girder?

[kokosnow]

I am working on a bridge project that there are no construction documents available. Does anyone know a nondestructive test method to determine the minimum yield point (Fy) for steel girders? Thanks.

 

[metengr]

kokosnow;
What I would do is to hire a local metallurgical lab/field services firm that can perform PMI (Positive Material Identification) and portable hardness testing to attempt to type the material. This is relatively inexpensive and can be done in bulk quantities (girders) with minor surface preparation.

Once you type the material chemical composition, you can evaluate the grade of carbon steel ultimate tensile strength from the portable hardness test results, and find a published yield strength.

 

[deco0404]

Kokosnow,

there are no NDT methods which will tell you anything about the yield strength. If you don't know what the material is, Positive material Identification will help. If you also do hardness testing you can get an indication of strength. with these two I'm sure you will have most of the information you will need to find the rest..

Dec

 

[stanweld]

In addition to the elements normally found by XRF PMI, you will need to determine carbon content. Depending on the year of original construction, you can almost always use A-36 as a starting point. The use of grade 50 materials were coming into vogue in the late 1960s and 1970s.

 

[EdStainless]

for these straight carbon steels PMI using portable optical emission spectrometer is needed to get carbon.
Otherwise they could drill small samples from various places for the carbon analysis.

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Plymouth Tube

 

[MikeMet]

There is a method called Automated Ball Indentation that is a very fancy type of calibrated hardness testing that provides yield strength and fracture toughness data.

http://ssmsystems.net/pdf/PVP170-2.pdf

http://jjmie.hu.edu.jo/files/v4n4/JJMIE-14-09_Revised(9)/JJMIE-14-09_ Modified.pdf

You can review and decide if you think it is appropriate. I feel is works well for carbon, low alloy steel and some other ferritic alloys. Not sure I would use on austenitic, PH sst or nickel alloys. There is, or was, a draft ASTM standard being developed.