Code of practice for high-temperature testing of weldments

Abstract

The present paper reports on a code of practice (CoP) for high-temperature testing of weldments for industrially relevant specimens. Novel aspects of the CoP include advice for testing weldment zones using different specimen geometries. Those specimens differ from the standard compact tension C(T) specimen recommended in the only available creep crack growth (CCG) testing standard ASTM E1457. Recommendations for the required number of tests, techniques for testing, treatment of test records, reduction of test data and data analysis are presented. Associated specimen selection guidelines for industrial creep crack initiation (CCI) and growth testing are also described. Validation tests carried out on P22 and P91 weldments, and base metals of 316H steel and C-Mn steel using relevant specimen geometries are briefly described. The CoP contains recommended K and C* solutions, Y functions and η factors, which are used to determine values of the fracture parameters K and C* for the specimen geometries considered. Information from these new tests, together with a review of previous CCG tests on non-standard geometries, have been used in recommending the best method of analysis for CCI and CCG data for a range of creep brittle to creep ductile welded materials.