Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Stainless steel, Co-Cr and Ni-Cr alloys have played an important role in many industrial sectors to combat environmental degradation. However, low hardness and poor wear properties have impeded their tribological and tribochemical applications. Conventional thermochemical treatments can be used to significantly harden these passive alloys but at the expense of their corrosion resistance due to precipitation induced depletion of Cr in the matrix. Research in 1980s led to the discovery of a new expanded austenite phase, i.e. so called S-phase with combined improvement in wear and corrosion resistance. Recent research has revealed that S-phase can be formed not only in stainless steels but also in Co-Cr alloys and Ni-Cr alloys. It is the purpose of this paper to critically review the S-phase surface engineering of stainless steels, Co-Cr alloys and Ni-Cr alloys. Particular attention will be paid to the structure, formation conditions, supersaturation, hardening mechanisms and metastability of...

S-phase surface engineering of Fe-Cr, Co-Cr and Ni-Cr alloys

Ce volume renferme les abstracts et index cumulatifs concernant de nombreux articles publies ces dernieres annees et relatifs au phenomene de diffusion dans l'etat condense

Defect and diffusion forum

Eddy current and total power loss separation in the iron–phosphate–polyepoxy soft magnetic composites

Inhibition effect of chromate on the passivation and pitting corrosion of a duplex stainless steel in LiBr solutions using electrochemical techniques

On the growth strain origin and stress evolution prediction during oxidation of metals

Oxidation of phosphated iron powders

The passive behaviour in artificial sea-water of Cr-implanted ( 4×10 16 ions/cm 2 , 60 keV) and non-implanted Ni was studied at room temperature by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). The transfer resistance obtained for the implanted specimen ( R t ∼5586 k Ω cm 2 ) is extremely enhanced compared to the corresponding value of the non-implanted Ni ( R t ∼94 k Ω cm 2 ) indicating a considerable increase in the protective efficiency of the implanted layer. The EIS spectra of ion-implanted Ni exhibit one capacitance loop while in the non-implanted Ni two distinct loops can be observed. These changes in EIS behaviour by the ion-implantation are related to the increase of the superficial layer density resulting in a more stable passive layer. Equivalent circuits were proposed to fit the impedance spectra and corresponding electrochemical parameters deduced. These findings were compared with the results obtained by analysis of the passive film formed on Ni, performed by XPS, and with previous investigations of similar alloys. It appears that the passive film formed on Ni consists of NiO and Ni(OH)2 whereas the chromium implantation leads to the formation in the passive state of Cr oxides and hydroxides which are responsible of the large increase of the transfer resistance.

J.F. Dinhut

Papers

On the growth strain origin and stress evolution prediction during oxidation of metals

Oxidation of phosphated iron powders

Influence of a chromium ion implantation on the passive behaviour of nickel in artificial sea-water: An EIS and XPS study

High temperature corrosion of some B2 iron aluminides

General approach on the growth strain versus viscoplastic relaxation during oxidation of metals