Notch toughness and how to address it

[trainguy]

Hi all.

If a high strength steel casting (ASTM A415) has inadvertently been welded to, I understand that low temperature notch toughness may be effected. Any guidance on how to evaluate how much it has, how to assess it, and potential methods of restoring the lost toughness?

Casting is part of a railcar truck (bogie).

tg

 

[metengr]

Are you sure about ASTM A 415?
Specification for Hot-Rolled Carbon Steel Sheets, Commercial Quality (Withdrawn 1970)

 

[trainguy]

Metengr,

Yes I am sure - sure that I messed up... its A514

tg

 

[trainguy]

Another clarification:

This is A514 steel plate that was cut and machined, not a casting.

Fy=90 000 psi
Fu=100 000 psi

According to :

https://www.onealsteel.com/alloy-steel-plate-a514.html

it is known for its high strength, weldability and toughness even at low temperatures.

Any thoughts?

tg

 

[EdStainless]

Do you know about the welding? How it was done and what filler was used?
Do you know which specific grade it is?

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P.E. Metallurgy, Plymouth Tube

 

[metengr]

The easy approach to this is to duplicate what you did in terms of welding by welding a coupon with the same material and joint configuration and perform bend and tensile testing. Similar to qualification of a Welding Procedure Specification, (if you had done this already you would know the outcome). You can even perform impact testing of the weld coupon to further quantify the fracture behavior of the weld region.

 

[trainguy]

The welding info is not at hand, but most likely SMAW with E7018 electrodes.

The item that was welded was a grade 8 nut, and this was eventually removed and all welds ground smooth with grain marks in the direction of principal stress.

Weld was in a very low stress region.

tg

 

[metengr]

I would perform portable hardness testing of the region where the welds were removed along with wet fluorescent MT.

 

[trainguy]

I really appreciate the free metallurgical advice...

Any suggestion of what I would compare the hardness value against?
Non-welded areas?

In the meantime, we will do a literature search of rail industry standards related to toughness of such assemblies.

Please do not hesitate to suggest what I often do on this board: (hire an expert!)

tg

 

[EdStainless]

Since it was removed I would go with metengr on this one.
Check for hard spots and cracks.
If you can't find either then feel comfortable.

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P.E. Metallurgy, Plymouth Tube