Abstract: A method of forming continuous or spot-sequenced lines across the surface of grain oriented steel strip by spark discharge from electrodes closely spaced from said strip, characterized in that the atmosphere through which the discharge is effected is inert. Preferably the inert atmosphere is nitrogen but other gases, e.g. argon may readily be employed.

Abstract: A method of removing heat from molten metal in which the metal is caused to flow freely within a gaseous media or vacuum over a body disposed within the metal stream such that any tendency for the metal to solidify during its passage is effective on the surface of said body against which the solidifying metal contracts into intimate contact therewith. The body may be forcibly cooled, e.g. by water. Accordingly, since the liquid metal is not enveloped by a channel or pipe, the solidifying shell tends to shrink on to the body, no gap is created, and this much higher heat transfer coefficients between the shell, the liquid metal, and the cooling body are achieved.

Abstract: This invention relates to a method of enhancing linear impressions formed in the surface of grain oriented electrical steel strip, by electrolytically etching said impressions with e.g. citric acid. The impressions may be formed by mechanical wheel scribing or by surface ablation, e.g. by spark discharge or laser treatment, and may be continuous or discontinuous in the form of spots or lines. In accordance with this invention therefore, the initial generation of light impressions in steel strip formed by mechanical wheel scribing or spark ablation techniques can readily be enhanced by application of the electrolytic etching technique to produce a material exhibiting values of power loss (reduced from the original unscribed loss value) which are substantially anneal-proof. In comparison, conventionally scribed material shows no resistance to a high temperature anneal as far as loss reduction is concerned.

Abstract: An apparatus and method for measuring a cross-sectional dimension or deviation from a predetermined shape of an elongated moving object. The apparatus is rotated about the object and includes a light source and photo-diode array. By continuous rotation of the apparatus about the object, deviations in the cross-sectional dimension are determined.

Abstract: A method of monitoring the degree of exposure of an electric arc within a furnace having a molten charge, e.g. an arc furnace or ladle furnace, in which characteristic frequency spectra of the waveforms from the supply associated with (a) arc-exposure and (b) arc-submersion are predetermined and in which signals (e.g. indicative of the arc current) emitted during operation are measured and processed and a comparison effected with a set level established from these characteristic signals whereby to provide an indication of the degree of arc exposure.The predetermined characteristic frequency spectra selected may be the harmonic content of the arc current.

Abstract: A method of shielding metal slabs from heat loss during inter-stand transport in a rolling mill with an inverted channel-shaped heat-insulating housing. The housing is sited over the roller table at a first position adjacent an upstream mill stand and is so dimensioned as to accommodate a slab entering through the trailing end of the housing as it issues from the stand; control means is provided operable (a) to cause the housing to travel along the table with the slab, (b) to arrest the housing adjacent the downstream mill stand whereby the slab exits thereto through the leading end of the housing and (c) to return to its said first position.

Abstract: A method of processing steel slabs in which the slabs are continuously routed through a furnace to a slabbing mill the slabs being sequentially charged through the bottom of the furnace by a reciprocating mechanism whereby on the upward stroke the slab charged engages and lifts the slabs piled above it and is then securely held (via jaws) until engaged itself in the next cycle by the succeeding slab. The top slab is discharged during each cycle whereby the number of slabs in the pile in consistent and all are heated on their exposed surfaces during their period in the furnace.This invention maximises the use of the residual heat from the cast slab where `sizing` is to be performed.