GB/T 24522-2009 Replaced National standards

GB/T 24522-2009 Metallic materials—Method of test for the determination of resistance to stable crack extension using specimens of low constraint

Publish Date: 2009-10-30 Implement Date: 2010-05-01 For services related to genuine standard inquiry, procurement, translation, and other related services in China, please Contact Us

Basic Information

Standard Code: GB/T 24522-2009

Standard Type: National standards

Standard Status: Replaced

is_force_gb: no

CCS Name: \n Test methods for the mechanical properties of metals

ICS Name: Mechanical testing of metal materials

Publish Date: 2009-10-30

Implement Date: 2010-05-01

Pages: 39 pages

Scope

This standard specifies the method for determining the steady crack propagation resistance δ5 and ΨC of low-constrained crack bodies in homogeneous metal materials during quasi-static loading. Compact tensile specimens and center-cracked tensile specimens have notches, and fatigue methods are used to prefabricate cracks. The tests are conducted under conditions of slowly increasing displacement.
The test methods described in this standard cover specimens that do not meet the size-insensitive requirements for fracture performance, such as relatively thin compact tensile specimens and center-cracked tensile specimens.
This standard provides a method for determining the crack propagation resistance curve (R curve). The determination of the fracture toughness characteristic value of compact tensile specimens is described in GB/T 21143, and the determination method of the fracture toughness characteristic value of center-cracked tensile specimens is given in Appendix D.
The determination of crack propagation resistance can be carried out using either the multi-specimen method or the single-specimen method. The multi-specimen method requires that each nominally identical specimen be loaded to a certain degree of displacement. The toughness crack propagation amount is marked, and then the specimen is opened to measure the crack propagation. As long as the accuracy requirements are met, the single-specimen method based on unloading flexibility and electric potential can also measure crack propagation. The recommended single-specimen method is described in GB/T 21143. Regardless of the method used, the aim is to obtain enough data points to adequately describe the crack propagation resistance behavior of the material.
The determination of δ5 is relatively simple and easy to implement. The δ5 results are represented by the resistance curve, showing the uniqueness of the specific limit range of crack propagation. Far from this limit range, the δ5 resist