摘要:
The present invention provides a method of producing a high permeability grain oriented electrical steel having excellent mechanical and magnetic properties. A hot band having a thickness of about 1.5 to about 4.0 mm has a chemistry comprising about 2.5 to about 4.5% silicon, about 0.1 to about 1.2% chromium, about 0.02 to about 0.08% carbon, about 0.01 to about 0.05% aluminum, up to about 0.1% sulfur, up to about 0.14% selenium, about 0.03 to about 0.15% manganese, up to about 0.2% tin, up to about 1% copper, and balance being essentially iron and residual elements, all percentages by weight. The band has a volume resistivity of at least about 45 μΩ-cm, an austenite volume fraction (γ1150° C.) of at least 20% and the strip has an isomorphic layer thickness of at least about 2% of the total thickness on at least one surface of the hot processed band. The band is rapidly cooled after the anneal prior to cold rolling at a rate of at least 30° C./second from 875-950° C. to a temperature below 400° C. The band is cold reduced in one or more stages with a final reduction of at least 80%, annealed, decarburized and coated with an annealing separator on at least one side. A final annealing provides stable secondary grain growth and a permeability measured at 796 A/m of at least 1840.
摘要:
The thermal flattening of grain oriented silicon steel which is in the semi-processed condition has improved magnetic properties after a stress relief anneal by using a low temperature and high tension flattening anneal. The flattening process is conducted at a temperature between 1000.degree. to 1435.degree. F. (540.degree. to 780.degree. C.) with a tension selected to produce a yield strength/tension ratio from above 5 to about 20 and preferably from 7 to 13. The yield strength of the material will vary depending on the length of the time at peak temperature but are typically from 400 to 4000 psi (29,200 to 292,000 gm/cm.sup.2). The material as thermally flattened will have at least about 10% stress. After a stress relief anneal above about 1450.degree. F. (785.degree. C.), the material has significantly improved core loss compared to conventional thermally flattened material. The material is particularly suited for wound transformer core applications.
摘要:
A process for improving the core loss of magnetic materials of the type having a plurality of magnetic domains and which may have an insulative coating such as a mill glass, an applied coating, or both. The magnetic material is subjected to a local heat treatment employing radio frequency induction heating, radio frequency resistance heating, or electron beam resistance heating to induce artificial boundaries. Thereafter, the magnetic material is subjected to an annealing treatment.
摘要:
In a method of producing a strip suitable for further processing to yield a (110)[001] grain oriented electrical steel from a thin strip such as a continuously cast thin strip the thin cast strip is processed to promote recrystallization from the surface layer of the strip (S=0) into the quarter thickness of the strip (S=0.2 to 0.3). The process parameters are selected so that the strain/recrystallization parameter (K*)−1, ≧about 6500 and wherein, ( K * ) - 1 = ( T HBA ) ln [ e . 0.15 exp ( 7616 T HR ) ln ( t c t f ) ] THBA is the annealing temperature of the strip (in °Kelvin), THR is the hot rolling temperature of the strip (in °Kelvin), {dot over (&egr;)} is the strain rate of hot rolling, ti is the initial thickness of the strip before hot rolling, and tf is the final thickness of the strip after hot rolling.
摘要:
Method for forming a laminate and a product formed thereof. A thin layer of oil is applied to a facing surface of at least one a plurality of adjacent laminations. The laminations are passed between a pair of rollers which apply sufficient pressure to remove excess oil between the facing surfaces. The air between the facing surfaces is displaced and the remaining oil forms a seal to prevent reentry of the air. The laminate is tightly held together to permit handling or fabrication without delamination.
摘要:
A process for improving the core loss of cube-on-edge grain oriented silicon steel. At some point in its routing after at least one stage of cold rolling and before the final high temperature anneal during which secondary grain growth occurs, the electrical steel is subjected to local annealing across its rolling direction creating bands of enlarged primary grains. These bands of enlarged primary grains regulate the growth of the secondary cube-on-edge grains in the intermediate unannealed areas of the electrical steel strip during the final high temperature anneal, and are themselves ultimately consumed by the secondary grains, providing a cube-on-edge grain oriented electrical steel with smaller secondary grains and reduced core loss.
摘要:
A process is taught for improving the core loss of magnetic materials of the type having a plurality of magnetic domains and an insulative coating thereon. The insulative coating may be a mill glass, an applied coating, or both. The magnetic material is scanned by the beam of a laser across its rolling direction so as to subdivide the magnetic domains without damage to the insulative coating.
摘要:
Non-oriented electrical steels are widely used as the magnetic core material in a variety of electrical machinery and devices, particularly in motors where low core loss and high magnetic permeability in all directions of the strip are desired. A method for producing a non-oriented electrical steel with low core loss and high magnetic permeability provides a steel that is produced from a steel melt which is cast as a thin strip or sheet, cooled, hot rolled and/or cold rolled into a finished strip. The finished strip is further subjected to at least one annealing treatment wherein the magnetic properties are developed, making the steel strip suitable for use in electrical machinery such as motors or transformers.
摘要:
A method of producing cube-on-edge oriented silicon steel strip and sheet from strand cast slabs, wherein a slab is prerolled at a temperature not exceeding 1673.degree. K. with a reduction in thickness up to 50%, and the prerolled slab is reheated to a temperature between 1533.degree. and 1673.degree. K. prior to hot rolling. The slab prerolling temperature, percentage of reduction in prerolling, and the reheat temperature are correlated in accordance with a specific equation in order to control the strain rate during prerolling and to obtain an average grain diameter not exceeding about 9 mm after reheating.
摘要:
The present invention relates to a method for producing a non-oriented electrical steel with improved magnetic properties and improved resistance to ridging, brittleness, nozzle clogging and magnetic aging. The chromium bearing steel is produced from a steel melt which is cast as a thin slab or conventional slab, cooled, hot rolled and/or cold rolled into a finished strip. The finished strip is further subjected to at least one annealing treatment wherein the magnetic properties are developed, making the steel sheet of the present invention suitable for use in electrical machinery such as motors or transformers.