This proposal is aimed at standardising creep crack growth (CCG) testing and data analysis techniques for weld metals of interest to high temperature plants The only existing CCG standard (ASTM E-1457) covers testing and analysis of 'parent' metals.
However, in practice cracking and failures in industrial components occur more frequently in welds and associated heat affected zones. The testing and analysi techniques for welds require special consideration because of their limited ductility and deformation zone size associated with defect incubation and propagation.
The proposal envisages testing welds and HAZs in 2.25Cr IMo and Grade 91 materials, both of which are used in high temperature plant components such as piping, headers and pressure vessels. The former is one of the most commonly used material for high temperature applications while the latter represents a high strength material with potential application for new advanced plant designs and as a replacement material for cracked components in existing plant. At present, in CCG testing in general various testing and data analysis techniques are used by different organisations which result in a large degree of laboratory to laboratory scatter giving less than satisfactory life predictions even for 'parent' materials. The situation is worse for welds and associated HAZs.
The objective of this proposal is to standardise these techniques for weldments of interest to European industry and draw up a Draft European Code of Practice.
Funding SchemeCSC - Cost-sharing contracts
1755 ZG Petten
114 28 Stockholm
2740-120 Porto Salvo
100 29 Stockholm