Donald Stone

Hydrogen attack in a 3Cr-1.5Mo steel at elevated temperatures

Abstract Specimens of a 3Cr-1.5Mo steel (where the composition is in approximate weight per cent) were exposed to hydrogen at 13.8 MPa and 600°C to examine their susceptibility to hydrogen attack. Special attention was given to the weld and heat-affected zones and to the cold-worked base material, all of which were expected to exhibit poorer resistance to attack than the base material. Several specimens were exposed under a simultaneously applied tensile stress which was expected to accelerate the rate of attack. The materials tested were found to be highly resistant to hydrogen attack. The thermodynamic and microstructural bases for this resistance are discussed. Previous findings on hydrogen attack in 2.25Cr-1Mo steels are included for comparison purposes.

Indentation Load Relaxation Studies of Thin Film-Substrate Systems

Results from indentation load relaxation (ILR) tests on thin film-substrate systems are reported. In the case of a 1 pum aluminum film on silicon, the data can be interpreted as reflecting both the properties of the film and the interface between film and substrate. Data from a 37μm TiN film on 304 SS are believed to reflect the combined behavior of the film and substrate.

The Nature of Class-A Creep Based on Load Relaxation, Constant Displacement Rate Tensile, and Constant Load Creep Data

ABSTRACT Load relaxation, tensile, and creep tests are utilized to examine the deformation behavior of an Al-4.6% Mg alloy in the class-A (alloy) regime. The solute-dislocation interaction manifests itself clearly as a yield drop and serrated flow during the tensile test. The possibility that constant load creep also involves inhomogenous flow is explored.