OBJECTIVE To study exposure to cobalt and chromium in saw maintenance rooms and test respiratory health among saw filers at lumber mills. Hard-metal lung disease is associated with cobalt in the manufacture of tungsten carbide tools; recently it has also been reported among tool maintenance workers. Lumber mills often use saws tipped with tungsten carbide or with a newer alloy, stellite (contai...

Layers of Fe-Cr-C Hard facing material containing various amounts of chromium were deposited on mild steel base metal. Optical Microscope (OM), Scanning Electron Microscope (SCM) and X-ray diffraction (XRD) were used to investigate the effect of chromium content of micro structural characteristics of Fe-Cr-C hard facing layers. The M7C3 carbide refinement mechanism exists on base metal. The exp...

the influence of aluminium on the microstructure of austempered ductile cast iron (adi) has been studied. the presence of well distributed graphite in the matrix, and a relatively high volume fraction of retained austenite are responsible for the good mechanical properties of the aluminium alloyed austempered ductile irons including excellent wear resistance, higher resistance to thermal shock,...

Single crystals of a new multinary chromium carbide, La21Cr8-2a Al b Ge7-b C12 (henicosa-lanthanum octa-chromium aluminium hexa-germanium dodeca-carbide), were grown from an La-rich self flux and were characterized by single-crystal X-ray diffraction. The face-centered cubic crystal structure is composed of isolated and geometrically frustrated regular Cr tetra-hedra that are co-centered within...

Background: Electrical Discharge Machining (EDM) is a well-established non-conventional machining process for the machining of electrically conductive and difficult-to-machine materials. But its applications are limited because of the slow machining rate and poor surface finish. Powder mixed EDM (PMEDM) is unitary of the recent progresses in the EDM process in which powder particles mixed in th...

Ledeburitic tool steel X210Cr12 was processed by passing through a semi-solid state with subsequent forming on hydraulic press, thus achieving fine-grained martensitic matrix, uniformly dispersed fine precipitates, and removal of sharp-edged primary chromium carbides. The hardness value over 700 HV10. decomposition austenite the promotion further carbide precipitation were carried out cryogenic...

Chromium carbide – nickel chromium powder Cr3C2-25wt.NiCr was plasma sprayed by a water-stabilized system WSP®. A series of experiments with variable feeding distance was carried out. Basic characterization of coatings was done by XRD, SEM and light microscopy plus image analysis. Microhardness was measured on polished cross sections. The main focus of investigation was on resistances against w...

in this study, the changes in microstructure of hp-nb cast heat resistant steel after 8 years of service at high temperatures were investigated. study of microstructure using optical microscopy (om) and scanning electron microscopy (sem) equipped with an energy dispersive spectrometry (eds) showed that the microstructure of this steel in as-cast condition includes an austenitic matrix, and that...

The growth of niobium carbide in austenite involves the diffusion of both niobium and carbon. These elements diffuse at very different rates. A model is presented for the overall transformation kinetics of niobium carbide precipitation in austenite that takes into account the multicomponent nature of the diffusion process while at the same time allows for the curvature of the transformation fro...

The raw materials traditionally used as sources of chromium carriers (ferrochromium, chromium oxide and chromium powder) in application chromizing processes present a high price and some difficulties for ferrochromium grinding. In this work there is an assessment of the effect that has the use of the products of a reduction aluminothermic chromium concentrate on the characteristics and properti...