Search
Filters
Close

High Temperature Hydrogen Attack Life Assessment Modeling and Inspection

Key elements of a technology initiative aimed at developing high temperature hydrogen attack (HTHA) assessment methodologies for equipment and piping operating in hot hydrogen service are presented. Two assessment methodologies have been developed: (1) a Screening Assessment and (2) an Advanced Assessment both of which predict the development of HTHA damage with time. The HTHA assessment methodologies utilize fitness-for-service (FFS) frameworks and are in good agreement with reported HTHA incidents in API 941RP and API 941TR for carbon steel and C-0.5Mo materials. The Screening Assessment provides an improved decision basis by classifying and ranking equipment operating in hot hydrogen service which are tied to recommended action and levels of concern. The Advanced Assessment models through-wall damage progression. Additionally the use of inspection findings as a means of risk mitigation and guidance on inspection interval decisions are also discussed. Select case studies are used to illustrate the advantages of the proposed methods. The developed methodologies provide an improved link between HTHA damage assessment and progression inspection and detection limits damage tolerance and operation severity.

Product Number: 51319-13326-SG
Author: James Johnson
Publication Date: 2019
$0.00
$20.00
$20.00
Also Purchased
Picture for Improved Models for Life Assessment Inspections and Repair-Replace Decisions For HIGH TEMPERATURE HYDROGEN ATTACK (HTHA)
Available for download

Improved Models for Life Assessment Inspections and Repair-Replace Decisions For HIGH TEMPERATURE HYDROGEN ATTACK (HTHA)

Product Number: 51319-13473-SG
Author: Raul Gonzalez
Publication Date: 2019
$20.00

HIGH-TEMPERATURE HYDROGEN ATTACK (HTHA) of steels is an extremely interesting topic in petrochemical industrial applications while a predictive physical model still does not exist. A number of studies carried out in the world are unambiguous confirmation of that statement. Bearing in mind multiple effects of hydrogen in certain metals the specific mechanism of high-temperature hydrogen attack embrittlement is manifested depending on the experimental conditions.The susceptibility of ASTM 204 Gr A steel to hydrogen-assisted cracking of refinery reactor retired was evaluated by mechanical fracture mechanics specimens. The material of zone with indication and zone without indications of the reactor was evaluated. Were loaded in tension and impact mechanical test to evaluate the probability of occurrence of the hydrogen-assisted cracking phenomenon. Fractography NDT and SEM-EDX analysis carried out on the fracture surfaces of the ruptured beams revealed was no evidence of the mechanisms of the crack propagation. Under both conditions the failure was cavity coalescence accommodated with plastic deformation. The results didn´t show the influence of hydrogen-induced embrittlement on the initiation of the fracture and the plasticity of the crack tip during the propagation of the crack where the latter becomes localized and uniform over the fracture surface. From the observations a three-stage crack propagation and lamination process and are proposed. Also the fracture toughness of the samples was evaluated by linear elastic fracture mechanics and the validity of the results are discussed. This result was very important to the refinery to develop plan inspections and make sound operations decisions based on the best available techniques.Keywords: Carbon steel corrosion HIGH TEMPERATURE HYDROGEN ATTACK (HTHA)