Westinghouse Electric Corporation

Karl Foster

Donald R Thornburg

Gary C Rauch

William T Reynolds

Robert M Delvecchio

Jack W Shilling

Wayne M Swift

A magnetostrictive transducer utilizing magnetostrictive material and a plurality of windings connected to current sources having a phase relationship so as to establish a rotating magnetic induction vector within the magnetostrictive material.

Magnetostrictive transducer

An alloy and a method of making the same are described. This alloy is suitable for use in an electrical magnetic induction apparatus. The alloy is characterized in that it may undergo an .alpha..revreaction..gamma. phase transformation upon heating to a sufficiently high temperature and in which the microstructure is oriented in the (110)[001] manner as described by Miller indices and is further characterized by a secondary recrystallized microstructure. The specification is replete with magnetic induction data as well as core loss data for alloys falling within the scope of the invention.

Secondary recrystallized oriented low-alloy iron

This is a method for making a low alloy iron having desirable magnetic characteristics suitable for electrical applications such as transformer cores. The ingot alloy has a relatively high (more than 50 ppm) sulfur and relatively high manganese (0.01-0.15%) and thus can be prepared from commercially available materials without further purification. While the sulfur in such a manganese containing alloy is not removed during final annealing (due to generally less than about 950.degree. C. final annealing temperatures of the primary recrystallization process) the use of a tensile stress (at least 200 psi) inducing glass coating provides for very low losses. The material contains significant amounts of both sulfur and manganese. Both the sulfur and manganese contribute towards the meltability of the alloy and the manganese contributes towards the workability (especially for cool rolling) of the sulfur containing material. Thus the material containing manganese and sulfur, has the high permeability of a low silicon primarily recrystallized material, but does not have the high losses normally associated with a relatively high sulfur containing magnetic material.

Loss reduction in oriented iron-base alloys containing sulfur

This is a low-alloy iron having desirable magnetic characteristics suitable for electrical applications such as transformer cores. This material has improved texture and reduced core losses. The alloys contain 0.6-1.0% silicon and 0.4-0.8% chromium along with controlled levels of manganese, sulfur, carbon and oxygen. These alloys are preferably processed to about 0.006 inch (0.015 cm) final gauge using schedules with three coldrolling steps. B.sub.10 values above 19 kG and 17 kG losses below 0.72 watts per pound are obtained with these alloys.

Oriented low-alloy iron containing critical amounts of silicon and

This is an ingot alloy composition and method suitable for making a low-alloy iron having desirable magnetic characteristics suitable for electrical applications such as transformers cores. The ingot alloy has relatively high (0.012-0.020%) sulfur and thus can be prepared with reduced melting cost (as compared to ingot alloys which are to have low sulfur content). To provide for good sulfur removal during processing, however, the manganese content of the ingot alloy must be kept very low (less than 0.01%, if the final annealing is to be performed at about (800.degree.-1000.degree. C.). The ingot alloy also contains 0.1-2% silicon, 0.1-2% chromium, 0.005-0.030% carbon, less than 0.004% oxygen and the balance essentially iron. The method provides for hot-rolling the above described ingot alloy at 900.degree.-1200.degree. C., annealing for 3-10 hours at 750.degree.-900.degree. C., cold-rolling with a 50-75% reduction, annealing for 3-10 hours at 750.degree.-900.degree. C., and cold-rolling with a 50-75% reduction to final thickness. The final annealing is performed for 24-72 hours at 800.degree. to 1000.degree. C.

Method of preparing an oriented low alloy iron from an ingot alloy

This invention is of a process and an intermediate alloy for making an oriented-low-alloy iron (primarily recrystallized) which obtains maximum (110) [001] texture and improved magnetic properties by controlling the sulfur, carbon, manganese, and oxygen contents in the intermediate alloy to certain critical narrow ranges. With alloys containing the 0.01-0.15 percent manganese normally found in commercially available iron, the optimum intermediate (prior to final anneal) sulfur level has been found to be 0.004-0.008 percent. This sulfur level is appropriate for such manganese contents for a wide variety of silicon and chromium content. Similarly an intermediate carbon level of between 0.002 and 0.020% has been shown to give the maximum texture and best properties. The oxygen level must be 0.005 percent or lower and should be held as low as practicable. With these levels of sulfur, carbon, manganese, and oxygen, the alloy can be processed by hot rolling at 900.degree.-1200.degree. C. (usually between 1000.degree.-1100.degree. C.), followed by either two or three cold rolling stages with the final cold rolling providing a 50-75 percent reduction, and with annealing at between 750.degree. C. and the A.sub.Cl temperature of the material between cold rollings. The alloy can also contain 0-3% cobalt and up to total of 2% chromium and silicon.

Method of preparing an oriented-low-alloy iron from an ingot of

Improved core losses at high operating inductions are obtained in (110) [001] oriented silicon iron through the application of a new coating to the finish gauge material and thereafter heat treating to effect transformation of the underlying steel to the (110) [001] orientation, desulfurizing the underlying steel as well as decarburizing the same. The coating, as fused, is characterized by excellent adherence and a high interlaminar resistance value.

Coatings for reduced losses in (110) [001] oriented silicon iron

An alloy and process are described for obtaining improved magnetic characteristics in iron-cobalt alloys. The iron-cobalt alloys described are characterized by a cube-on-face texture, primary recrystallized and normal grain growth microstructure. Processes are described which include both a single stage cold working and a multiple stage cold working in order to obtain the desired texture in the finished alloy.

Method of producing doubly oriented cobalt iron alloys

A process is described in which an iron-silicon alloy capable of being heat treated to produce a cube-on-edge (110) [001] grain orientation is treated to produce improved core losses when the material is under high operating inductions. The process steps include cleaning the surface of the steel of finish gauge thickness, applying a coating to the surface of the steel which is non-reactive with the surface and promotes decarburization, heating to a temperature sufficiently high to effect secondary recrystallization texture development and decarburization and cooling to room temperature. Data are included which demonstrate the improved core losses exhibited by these materials so treated when tested at high operating inductions.

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Pittsburgh, PA, United States of America

Karl Foster