Unknown steel and how to identify them

[Paul Checa]

Hi all I was trying to do a spark test but got pretty similar results and was hoping I could get some help from the masters in the forum...

So I found what I believe to be a piec of spring steel from a truck's suspension in the highway and brought it back to the shop and performed a spark test on it only to be more confused it. I've attached a video where you can see me performing the test. 

 

The first is 5160 steel 

The second is the steel I found on the highway 

The third is a piece of rebar. 

 

I would love to read your comments. 

 

Thanks! 

[Joël Mercier]

What I'd do is use new known steels but if I was to use this steel I'd:

Cut a few test coupons around 1/8" thick. Normalize at average carbon steel temperatures. Austenize at different temperatures around 1500°f. Grind the coupons flat and clean. Test hardness. Break all test coupons and examine grain.

 

It may just be abrasion resistant steel like ar500. 

[Alan Longmire]

Joel offers good advice, as usual.  The spark test is almost impossible to do well with an angle grinder.  It calls for a large-ish stone wheel grinder (or a belt grinder) running around 1350-1600 RPM for ease of seeing the actual pattern.  Angle grinders at their smaller wheel size and much faster RPM tend to make a dazzling spray of sparks on whatever you're cutting.  

 

All I could tell was the mystery steel is alloyed more highly than the rebar, and a bit differently than the 5160.  Could be 6150, often used for heavy truck springs, could be AR plate, used for the edge of road grader blades and such.  6150 is great, although hard to forge.  AR plate is not good for blades or forging.  

[Paul Checa]

So I guess I'm doing some cupón normalizing! 

 

Thanks guys! 

3 hours ago, Alan Longmire said:

Joel offers good advice, as usual.  The spark test is almost impossible to do well with an angle grinder.  It calls for a large-ish stone wheel grinder (or a belt grinder) running around 1350-1600 RPM for ease of seeing the actual pattern.  Angle grinders at their smaller wheel size and much faster RPM tend to make a dazzling spray of sparks on whatever you're cutting.  

 

All I could tell was the mystery steel is alloyed more highly than the rebar, and a bit differently than the 5160.  Could be 6150, often used for heavy truck springs, could be AR plate, used for the edge of road grader blades and such.  6150 is great, although hard to forge.  AR plate is not good for blades or forging.