Internal and surface damage of multiphase steels and pure iron after electrochemical hydrogen charging

High strength steels appear to be even more prone to hydrogen embrittlement (HE). In this work, pure iron and a ferrite–bainite steel were charged electrochemically using various electrolytes and combinations of current density and charging time to identify the experimental conditions where blister formation occurred. The appearance and propagation of cracks inside the sample were studied also by means of high resolution scanning electron microscopy. The study was repeated for a dual phase (DP) steel; a TRIP steel and a high strength low alloy (HSLA), which allowed to get an indication on the effect of variable microstructural characteristics.     

Operational properties of tool steels after combined volume-and-surface strengthening

The durability of tools can by improved by the introduction and development of methods of surface hardening. The industry is already performing hardening by highly concentrated energy sources such as laser beams, plasma jets, electron beams. However, this kind of hardening cannot yet replace completely volume heat treatment in tool manufacturing. This is connected with the short time of the temperature action of the highly concentrated energy source, which leads to incomplete structural and phase transformations that determine the operational properties of tool materials. An important way for improving the tool hardening consists in the development of combined technological processes including volume and surface heat treatment. The present paper is devoted to this problem. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 2–6, May, 1997.     

Properties of surface layers of manganese steels after electron-beam treatment

A promising direction for improving the operating characteristics of steels consists in obtaining a surface layer by differentiated treatment as a result of which, due to the combination of the total and local effects, tough and ductile structures alternate in a preassigned order. The present paper concerns the investigation of surface layers in manganese steels subjected to an electron-beam treatment.     

The effects of surface roughness on sheet steels after phosphating

Surface characteristics of phosphated sheet steels are primarily responsible for variable paint performance. A Three-Dimensional Surface Characterization Technique is introduced to characterize the surface topography of the phosphated sheet steels. By using this new technique, the influences of the initial surface topography, temperature and immersion time on the surface finish are studied. The frequency domain analysis is also performed to identify the basic characteristics of a phosphating process.     

Structure of hardened carbon steels after plasma heating of the surface

The structure of the zone of plasma effect and the corresponding scattering of the values of the microhardness are determined by the variety of the processes of formation and decomposition of microchemically inhomogeneous austenite under the conditions when the diffusion processes have not been completed. The preservation of high-carbon microregions in the places of pearlite and high cooling rates of austenite provide martensite with a high microhardness (800–1250H depending on the carbon content) that exceeds considerably the microhardness of martensite obtained after volume hardening. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 2–4, June, 1997.     

Fatigue strength during compression of tool steels

Metal Science and Heat Treatment -