Brittle fracture in vessels

[BrittleSteel]

Hi everyone,

I was reading this CSB report that came out last year:

https://www.csb.gov/husky-energy-superior-refinery...

One of the issues they mentioned in the report is that since the vessels were made of SA-212B and SA-201, brittle fracture occurred instead of a fish mouth rupture thus pieces of steel may dangerous projectiles.

My understanding is that this explosion occurred due to a fire case not because of a blocked discharge.

My first question is, did the metal projectiles get its energy from the heat generated rather than pressure? usually when some think about projectiles from a vessel failure many think of an overpressure scenario.

My second question is if the pressure vessel was designed for a fire case, would this failure still had occurred?

Last question is any pressure vessel that is made of a brittle material can fail in a similar manner if it's possible that enough energy is generated in the vessel to exceed its energy dissipation capacity. Is this correct?

 

[SJones]

The last question: brittle fracture will occur when the fracture toughness of the material is exceeded. In a very loose sense, that might be taken as being “unable to dissipate sufficient energy” by plastically deforming without fracturing. Try a Google on “failure assessment diagrams”.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[blacksmith37]

A 212 and A201 are very old material specifications and toughness can be and often was ,very low.