Boron Content in Steel

[EnquiringEngineer]

Hi all,

I've seen in specifications that often boron is limited to 0.0008% in steel. What are the ramifications of going above this limit, say to 0.0012%?

It looks like high boron content steel might have specific requirements for welds?

Just trying to evaluate whether it's a big concern, I.e. whether there are structural concerns.

Thanks!

 

[kingnero]

Boron has a negative effect on weldability, and will create cracks and fissures. All steel mills are well aware of this, and don't like it as B also has a positive effect on pouring/casting. Can't help you with the specifics of going a few thou of a % over the limit...

 

[EnquiringEngineer]

Interesting. In this case the contractor has undertaken 100% ultrasonic testing of all welds and it's all passed - no cracking detected. Does that mean that there's no major concerns?

Thanks for your help.

 

[kingnero]

I'd say you need an expert metallurgic opinion on your particular case. UT OK does not mean everything else is OK. Also, anonymous internet replies carry no real weight in case of problems...

 

[mfgenggear]

Lots of info

https://www.totalmateria.com/en-us/articles/boron-in-steel-2

 

[EdStainless]

Passing UT mean that they didn't find any cracks larger than they calibrated for.
NDT is a matter of probabilities.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[mfgenggear]

Enquiring engineer

Run magnetic inspection for ferretic steels
And penetrant inspect for stainless steels
And including radiographic inspection.

And add a NDT specification for allowable defects.
And procedure for each inspection method.

 

[SWComposites]

Enquiring engineer,
what type of structure are you dealing with?
What is the criticality?
What type of steel?
How did the contractor qualify their NDT process?
“Passed” what criteria?