DIN EN ISO 6892-2:2011-05

In this part of ISO 6892, two methods of testing speeds are described. The first, Method A, is based on strain rates (including crosshead separation rate) with narrow tolerances (± 20 %) and the second, Method B, is based on conventional strain rate ranges and tolerances. Method A is intended to minimize the variation of the test rates during the moment when strain rate sensitive parameters are determined and to minimize the measurement uncertainty of the test results. The influence of the testing speed on the mechanical properties, determined by the tensile test, is normally greater at an elevated temperature than at room temperature. Traditionally, mechanical properties determined by tensile tests at elevated temperatures have been determined at a slower strain or stressing rate than at room temperature. This part of ISO 6892 recommends the use of slow strain rates but, in addition, higher strain rates are permitted for particular applications, such as comparison with room temperature properties at the same strain rate. During discussions concerning the speed of testing in the preparation of this part of ISO 6892, it was decided to consider deleting the stress rate method in future revisions. This part of ISO 6892 specifies a method of tensile testing of metallic materials at temperatures higher than room temperature. This document (EN ISO 6892-2:2011) has been prepared by Technical Committee ISO/TC 164 "Mechanical testing of metals", Subcommittee 1 "Unaxial testing" (secretariat: AFNOR, France) and has been adopted under the Vienna Agreement by ECISS/TC 101 "Test methods for steel (other than chemical analysis)" (secretariat: AFNOR, France). Regarding German collaboration, the responsible Working Committee is NA 062-01-42 AA "Zug- und Duktilitätsprüfung für Metalle" ("Tensile and ductility testing of metals") at the Materials Testing Standards Committee (NMP).