Reliability and limitations of the non destructive replica technique for the assessment of creep damage in welded components
conference paper
Within a Joint Industrial Programme (JIP) with 12 partners, including inspection companies, engineering companies, end users and a notifying body, the reliability of the replica technique for the assessment of creep damage in welded joints has been assessed. The programme was initiated where significant differences in the interpretation of replicas were addressed and replication was characterised as a not a reliable tool. It is curious that for the preparation and interpretation of replicas persons do not need to be qualified, although a specific expertise is necessary for a proper preparation and interpretation. There are also no international or national certifying bodies. Companies have their own standards. For other N.D.E. methodologies certain levels of competence are always required. Within the JIP the practical work was performed in "Workshop" sessions and 6 inspection companies were involved, covering more than 50% of the replica activities in Western-Europe. For a realistic approach the replication activities were performed on creep damaged welded ferritic, martensitic and austenitic components and not on small creep specimens etc. Starting with the individual company procedures for replica preparation and damage assessment, unreliable results were obtained with an unacceptable scatter. The main source for the scatter was the damage assessor and the method of replica preparation was not. With a new procedure, developed within the programme and accepted by all the companies, the scatter has been dramatically reduced to an acceptable level. Finally the programme resulted in a guideline for the preparation and damage assessment of replicas of ferritic and austenitic welded joints. It also includes flow charts to distinguish creep damage from other types of damage.
Topics
TNO Identifier
240800
ISBN
9780791842874
Publisher
ASME
Article nr.
CREEP2007-26310
Source title
ASME Pressure Vessels and Piping Conference, 8th International Conference on Creep and Fatigue at Elevated Temperatures, PVP-2007/CREEP8, 22-26 July 2007, San Antonio, TX, USA
Collation
6 p.
Pages
567-572
Files
To receive the publication files, please send an e-mail request to TNO Repository.