The surface properties of powder particles of 316L steel and Inconel 718 alloy applied in additive technologies have been studied, including interaction with hydrogen of specimens fabricated from these powders by selective laser melting.

The influence of hydrogen on the strength and ductility of 30KhGSA and EI659 steels in quasi-static and shock-loading tests was studied experimentally. The sensitivity of the steels to hydrogenation in air under normal pressure or in hydrogen at a pressure of 25 MPa was determined from the results of tests of as-received and pre-hydrogenated samples at a temperature of 773 K and a hydrogen pressure of 50 MPa for 24 h. It is found that EI659 steel doped with tungsten and vanadium is less sensitive to hydrogenation than 30KhGSA steel doped with manganese and chromium.

The article presents results of comparative tests for determination of deuterium fluxes permeating through walls of austenitic stainless steel AISI304 (DIN 1.4301) chamber and Al2O3 based ceramic F99.7 chamber. Both chambers represent a piece of empty set26x empty set22x117 mm(3) tube with spherical bottom ending. It is shown that at 773 K and deuterium pressure of 1200 mbar the permeated deuterium flux through the stainless steel chamber constituted 8.10(-5)cm(3)/s, while the flux through ceramic one it did not exceed the sensitivity of the measurement method threshold, namely similar to 1.5.10(-7)cm(3)/s. The ceramic chamber turned out to survive more than 10(3) cycles of heating up to 773 K with no damages. It did not lose its impermeability up to 10 bar of internal deuterium pressure. The authors also present test results of a prototype bed for reversible tritium storage. The bed's case was made of alumina based ceramic F99.7, titanium being used as tritide making metal and high frequency induction used for heating of tritide metal.

A brief review of data for the influence of helium on the hydrogen sorption and mechanical properties of nickel and 12Kh18N10T steel is presented. When in the metallic matrix, helium considerably deteriorates the ductility of these metals. It is shown that 3He present in 12Kh18N10T steel generates high-energy hydrogen traps.

The paper presents research results related to the impact of high-pressure hydrogen (80 MPa) and radiogenic He-3 and their synergetic effect on mechanical properties and structure of CrNi40MoCuTiAl alloy within the temperature range from room temperature to 873K.The samples of three different He-3 concentrations have been prepared for research approximate to 30, approximate to 80 and approximate to 19 0 appm. The buildup of He-3 has been fulfilled using tritium trick technique.The tests at room temperature have shown the increasing conventional yield strength (sigma(0.2)) and decreasing plasticity characteristics (total elongation delta(5) and reduction of area psi) depend on He-3 concentration increasing. However at 873 K test temperature the alloy with the maximum He-3 (approximate to 190 appm) concentration turned out to be more plastic than the alloy with He-3 approximate to 30 and 80 appm concentration.

We present some results of studying the influence of high-pressure hydrogen (80 MPa), radiogenic 3 He (with concentrations up to 130 appm), and their joint action on the mechanical properties and structure of 12Kh18N10T steel in the temperature range from 293 to 873 K. We describe the procedure of tests of specimens containing 3 He. It has been established that the joint action of hydrogen and 3 He affects slightly the ultimate strength of the specimens. Saturation of steel with radiogenic 3 He by the method of “tritium trick” increases its yield strength. Hardening of the steel caused by helium increases with temperature and 3 He concentration and, at 873 K, is accompanied by substantial embrittlement. We also present results of the fractographic analysis of specimens tested under different conditions.

The paper presents results of tritium-structural materials interaction modeling by simultaneous exposure to radiogenic helium-3 and hydrogen (both dissolved and external). This method of synergetic effect of radiogenic helium-3 and hydrogen is a radiation-safe technique to study the tritium impact on mechanical properties of structural materials. Applicability of the method is illustrated by technique and research results on the impact of high-pressure hydrogen (80MPa), helium-3 (concentration similar to 140appm) and their synergetic (hydrogen+He-3) effecs on mechanical properties of CrNi40MoCuTiAl alloy in temperature range from 20 to 600 degrees C It has been shown that joint effect of radiogenic helium-3 and hydrogen on mechanical properties of alloy can not be represented as the result of a simple summation of helium and hydrogen embrittlement. Proposed technique of synergetic impact of radiogenic helium-3 and hydrogen allows more correct simulation and investigation in the tritium impact on mechanical properties of materials than individual research in helium or hydrogen embrittlement.

Investigations into the radiogenic helium effect on mechanical properties and structure of the Pd-alloy B-1 have been carried out. For accelerated accumulation of helium in the alloy up to 3190 appm (simulating a long-term permeator operation (∼6 years) when cleaning up the international thermonuclear experimental reactors (ITER) spent D–T fuel mix) the alloy was saturated with tritium at room temperature. High tritium solubility was thus achieved at relatively low pressures. Research results showed that radiogenic helium available in the specimens causes their hardening with significant decrease in plasticity. Structural changes in the specimen material have not been found.

This paper presents research of the hydrogen gas effects on physical and mechanical properties of the precipitation-hardened nickel alloys EP741 and EP99 at pressures up to 65 MPa and temperatures up to 840 degrees C. It has been shown that conventional yield strength, tubular-shaped sample fracture stress and long-term strength are not practically affected by hydrogen. The characteristics of alloy ductility are more susceptible to hydrogen effect. EP741 alloy Is especially susceptible to the hydrogen environment effect at temperature of 460 degrees C, and EP99-at temperatures of 20 degrees C and 460 degrees C. Hydrogen permeability relationships for alloys in a wide range of temperature and pressure were obtained. (C) 1999 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.