ASTM G39-99(2021)
Standard Practice for Preparation and Use of Bent-Beam Stress-Corrosion Test Specimens

Standard No.

ASTM G39-99(2021)

Release Date

2021

Published By

American Society for Testing and Materials (ASTM)

Latest

ASTM G39-99(2021)

Scope

1.1 This practice covers procedures for designing, preparing, and using bent-beam stress-corrosion specimens. 1.2 Different specimen configurations are given for use with different product forms, such as sheet or plate. This practice is applicable to specimens of any metal that are stressed to levels less than the elastic limit of the material, and therefore, the applied stress can be accurately calculated or measured (see Note 1). Stress calculations by this practice are not applicable to plastically stressed specimens. NOTE 1—It is the nature of these practices that only the applied stress can be calculated. Since stress-corrosion cracking is a function of the total stress, for critical applications and proper interpretation of results, the residual stress (before applying external stress) or the total elastic stress (after applying external stress) should be determined by appropriate nondestructive methods, such as X-ray diffraction (1).2 1.3 Test procedures are given for stress-corrosion testing by exposure to gaseous and liquid environments. 1.4 The bent-beam test is best suited for flat product forms, such as sheet, strip, and plate. For plate material the bent-beam specimen is more difficult to use because more rugged specimen holders must be built to accommodate the specimens. A double-beam modification of a four-point loaded specimen to utilize heavier materials is described in 10.5. 1.5 The exposure of specimens in a corrosive environment is treated only briefly since other practices deal with this aspect, for example, Practices D1141, G30, G36, G44, G50, and G85. The experimenter is referred to ASTM Special Technical Publication 425 (2). 1.6 The bent-beam practice generally constitutes a constant strain (deflection) test. Once cracking has initiated, the state of stress at the tip of the crack as well as in uncracked areas has changed, and therefore, the known or calculated stress or strain values discussed in this practice apply only to the state of stress existing before initiation of cracks. 1.7 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (For more specific safety hazard information see Section 7 and 12.1.) 1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ASTM G39-99(2021) Referenced Document

• ASTM D1141 Standard Practice for the Preparation of Substitute Ocean Water
• ASTM G30 Standard Practice for Making and Using U-Bend Stress-Corrosion Test Specimens
• ASTM G36 Standard Practice for Evaluating Stress-Corrosion-Cracking Resistance of Metals and Alloys in a Boiling Magnesium Chloride Solution
• ASTM G44 Standard Practice for Exposure of Metals and Alloys by Alternate Immersion in Neutral 3.5?% Sodium Chloride Solution
• ASTM G50 Standard Practice for Conducting Atmospheric Corrosion Tests on Metals
• ASTM G85 Standard Practice for Modified Salt Spray (Fog) Testing

ASTM G39-99(2021) history

• 2021 ASTM G39-99(2021) Standard Practice for Preparation and Use of Bent-Beam Stress-Corrosion Test Specimens
• 1999 ASTM G39-99(2016) Standard Practice for Preparation and Use of Bent-Beam Stress-Corrosion Test Specimens
• 1999 ASTM G39-99(2011) Standard Practice for Preparation and Use of Bent-Beam Stress-Corrosion Test Specimens
• 1999 ASTM G39-99(2005) Standard Practice for Preparation and Use of Bent-Beam Stress-Corrosion Test Specimens
• 1999 ASTM G39-99 Standard Practice for Preparation and Use of Bent-Beam Stress-Corrosion Test Specimens