Hydrogen embrittlement of steels: II. Effect of strength

The hydrogen embrittlement resistances of 35KhGM steel in states of different strengths are compared. The effect of strength on the fracture mechanism and kinetics in the steel during hydrogen embrittlement is demonstrated using a joint analysis of acoustic emission signals and stress-strain diagram during tension, metallography, and fractography.     

Stress corrosion cracking of zirconium cladding tubes: I. Proximate local SCC testing method

The mechanisms and kinetics of corrosion fracture of thin-wall cladding tubes of zirconium alloys in a methanol-iodine medium are determined by a direct comparison of the acoustic emission parameters with the characteristics of accumulated corrosion defects in a material during stress corrosion cracking tests. The main types of corrosion defects (nucleation, development, interaction) are revealed and quantitatively described. A general sequence of nucleation and development of corrosion defects is established for all types of tubes.     

Twin structures in copper after shock and Shockless high-rate loading

The structure of copper formed after high-rate loading up to pressures of 20–80 GPa with a strain rate of 10⁵–10⁹ sec^?1 is considered. In situations with pressures above 20 GPa and strain rates above 10⁶ sec^?1, the deformation twins are grouped into packets, which are seen in an optical microscope as parallel bands of localized strains inside individual grains. The number of bands in the structure increases with increasing grain size and strain rate, with decreasing sample temperature, and with increasing period of sample loading. The characteristic time of formation of twin bands in copper is estimated as 0.3 µsec.     

Stress corrosion cracking of zirconium cladding tubes: IV. Effect of hydrogen saturation

The effect of hydrogen saturation on the stress corrosion cracking (SCC) resistance of zirconium cladding tubes in an iodine-containing medium is studied. Comparative SCC tests are performed for tubes produced from E110 and E635 alloys with various hydrogen contents (up to 400 ppm). Hydrogen is shown to decrease the SCC resistance of the tubes predominantly because of the activation of pitting formation processes.     

Methods for Analyzing Deformation and Fracture Processes of Thin-Walled Parts from Low-Strength Alloys

The presented complex methods for analyzing the processes of deformation and fracture, including the evaluation of process ductility and measurement of crack resistance characteristics, are based on joint analysis of loading diagrams, acoustic emission signals, and fractures of articles fabricated from low-strength alloys. The possibilities of the methods in evaluation of fracture resistance of thin-walled parts from zirconium alloys are shown. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 43 – 50, April, 2005.     

Hydrogen embrittlement of steels: I. Analysis of the process kinetics using acoustic emission measurements

A technique is presented for studying the process of delayed hydrogen embrittlement of steels by acoustic emission (AE) during galvanic hydrogen saturation of a metal. Examples of estimating the hydrogen embrittlement resistances of steels with various strengths are estimated from AE measurements.