Overheated components due to fire outbreak
Overheated components due to fire outbreak
(OP)
Dear all,
We had an issue of fire outbreak on the equipment that consisted of component made of A516 grade 70, A516 Grade 60, A106 Grade B and A105 materials. The issue is if the components had been heated to above Ac1 line ..approximately 723C and cooled slowly...ie air or furnace cool...and not rapidly quenched. Does the affect of temperature really an issue if the structure is maintained as ferrite and pearlite and the hardness was from 140 to 170 Hv...which are within the specification. Was the integrity of the material sacrificed?
We found some component consist of patches of martersite which indicted that the temperature had reached above 723C or may be to a fully austenitizing temperature. We will tackle this region separately.
We had an issue of fire outbreak on the equipment that consisted of component made of A516 grade 70, A516 Grade 60, A106 Grade B and A105 materials. The issue is if the components had been heated to above Ac1 line ..approximately 723C and cooled slowly...ie air or furnace cool...and not rapidly quenched. Does the affect of temperature really an issue if the structure is maintained as ferrite and pearlite and the hardness was from 140 to 170 Hv...which are within the specification. Was the integrity of the material sacrificed?
We found some component consist of patches of martersite which indicted that the temperature had reached above 723C or may be to a fully austenitizing temperature. We will tackle this region separately.





RE: Overheated components due to fire outbreak
No. I would perform a visual examination to check for buckling or warpage. If nothing structural is found, the material will be suitable for service.
RE: Overheated components due to fire outbreak
Thank you very much for the comment. For the region that contained martensite we will do thorough investigation by replica and hardness measurement to see whether martensite is only on the surface or through the thickness.
RE: Overheated components due to fire outbreak
That is a good approach for these locations. I would also suggest surface NDT to ensure no cracks from exposure to quenching when water was used to extinguish the fire.
RE: Overheated components due to fire outbreak
It can be very difficult to get all of the details correct.
I only had to do this once, we focused on a few major pieces of equipment and simply striped all of the smaller and aux systems and piping and replaced them. Our insurance company was actually a big help, they had an expert available to assist us.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: Overheated components due to fire outbreak
Thank you ..yes..NDT is a part of our next approach.
Edstainless
Thank you for the info...we are working closely with RCA (Root Cause analysis) group and insurance company. My task is to perform hardness, replica and NDE. Complete Fire damage assessment is a must before the equipment can be put in service again.