Minimum Carbon content for API 5L X60
Minimum Carbon content for API 5L X60
(OP)
Dear all,
Anyone know about the minimum carbon Wt% for API 5L X60. According to the specification the maximum carbon content 0.28 wt%. My PMI results shows the carbon content of 0.05 wt%. However the microstructure is tempered martensite with the hardness of 210HV, Yield strength of 520 MPa, UTS=564 MPa and elongation is 31.5%. Mn content is 1.33 wt.%. Is the carbon content sufficient to form martensite? Is the carbon content represent hardness and UTS value?
Any comment is highly appreciated.
Thank you
Anyone know about the minimum carbon Wt% for API 5L X60. According to the specification the maximum carbon content 0.28 wt%. My PMI results shows the carbon content of 0.05 wt%. However the microstructure is tempered martensite with the hardness of 210HV, Yield strength of 520 MPa, UTS=564 MPa and elongation is 31.5%. Mn content is 1.33 wt.%. Is the carbon content sufficient to form martensite? Is the carbon content represent hardness and UTS value?
Any comment is highly appreciated.
Thank you
RE: Minimum Carbon content for API 5L X60
RE: Minimum Carbon content for API 5L X60
RE: Minimum Carbon content for API 5L X60
Kingnero ..Laser Induced Breakdown Spectroscopy (LIBS) by Brunker claims that it can detect carbon but I am also worried about the accuracy. LIBS using laser instead of XRF. I will reconfirm using spark spectroscopy.
Are you sure of the carbon content? Most PMI equipment (XRF) cannot accurately measure C.
Weldstan..Agree with you and I will confirm by spark spectroscopy. Will update the results when available.
Thank you for the comments.
RE: Minimum Carbon content for API 5L X60
RE: Minimum Carbon content for API 5L X60
Weldstan...LIBS used laser to spark under argon environment and analyse using spectroscopy. I did not analyse using LIBS but I used XRF. I doubt about the value for carbon as it is too low to get the measured mechanical properties and microstructure.
RE: Minimum Carbon content for API 5L X60
RE: Minimum Carbon content for API 5L X60
RE: Minimum Carbon content for API 5L X60
RE: Minimum Carbon content for API 5L X60
This may well be TMF seamless.
My guess is that you misinterpreting the micros. Yes, there are multiple phases but they are not traditional martensite.
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RE: Minimum Carbon content for API 5L X60
Attached is the microstructure of the pipe API 5L X60
RE: Minimum Carbon content for API 5L X60
RE: Minimum Carbon content for API 5L X60
RE: Minimum Carbon content for API 5L X60
RE: Minimum Carbon content for API 5L X60
blacksmith37...Thank you for your comment...Nb=0.008, Ti=0.011, V=0.021
Nb+V+Ti=0.0409<0.15.
I am sorry, I am familiar with microalloyed steel. Can anybody comment on the microstructure?. What microstructure is it and in what condition the material was supplied. It looks like martensite/bainite with ferrite and carbides or could it be acicular ferrite with carbides.. We lost the mill certificate as it was manufactured in late 80s.
There is a mistake in my statement. We are not using XRF far the analysis. I have to check it out.
Based on the carbon content, if the result is true, is 0.05% acceptable for API 5L X60?
Another issue is that, should the material is ERW can we see the microstructure of the weldment by macro etching?
RE: Minimum Carbon content for API 5L X60
Steve Jones
Corrosion Management Consultant
www.linkedin.com/in/drstevejones
All answers are personal opinions only and are in no way connected with any employer.
RE: Minimum Carbon content for API 5L X60
So I conclude as follows:
1. The composition meet the specification for API 5L X60.
2. Seamless
3. Complex microstructure with martensite/bainite and acicular ferrite.
4. Supplied in the TMF condition.
Thank you very much for the comments. I really appreciated them.
RE: Minimum Carbon content for API 5L X60
That seems exceedingly complex for X60. Is the metallurgist performing the assessment familiar with this type of steel?
"Everyone is entitled to their own opinions, but they are not entitled to their own facts."
RE: Minimum Carbon content for API 5L X60
Take a look at the quoted yield strength - it's heading towards higher grade territory
Steve Jones
Corrosion Management Consultant
www.linkedin.com/in/drstevejones
All answers are personal opinions only and are in no way connected with any employer.
RE: Minimum Carbon content for API 5L X60
Comments are highly appreciated.