GB/T 6803-2023 Test method for drop-weight test to determine nil-ductility transition temperature of ferritic steels
1 Scope
This document specifies the principles, specimen, test device, test requirements, test procedures, evaluation of test results, and test reports for the test method for drop-weight test to determine nil-ductility transition temperature of ferritic steels.
This document is applicable to the determination of the nil-ductility transition temperature of ferritic steel products (including plates, profiles, cast and forged steels) with a thickness of not less than 12 mm.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 984 Hardfacing electrodes for shielded metal arc welding
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing
JJF 1445 Calibration specification for falling weight impact testing machines
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
ferritic steel
all α-Fe steels
Note: It includes non-austenitic steels such as martensitic, pearlite and bainite.
3.2
nil-ductility transition (NDT) temperature
maximum temperature at which the specimen breaks when the drop-weight test is carried out according to the this method
4 Principle
Each specimen in a set of specimens of a given ferritic steel material is subjected to a single drop-weight impact load at a selected temperature, causing the specimen to produce a fixed deflection, and the maximum temperature at which the specimen breaks, called as the NDT temperature, is determined.
5 Specimen
5.1 Sampling position and direction of specimen
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Principle 5 Specimen 6 Test equipment 7 Test requirements 8 Test procedure 9 Evaluation of test results 10 Test report Annex A (Normative) Dimensions and test conditions of drop-weight auxiliary specimen Annex B (Informative) Drop-weight specimens of butt welded joints Bibliography
