What is CRGO?
Cold Rolled Grain Oriented Steel, is an Electrical steel, also called lamination steel, silicon electrical steel, silicon steel, relay steel or transformer steel, is specialty steel tailored to produce certain magnetic properties, such as a small hysteresis area (small energy dissipation per cycle, or low core loss) and high permeability.
What is the metallurgy of CRGO?
Electrical steel is an iron alloy which may have from zero to 6.5% silicon (Si:5Fe). Commercial alloys usually have silicon content up to 3.2% (higher concentrations usually provoke brittleness during cold rolling). Manganese and aluminum can be added up to 0.5%.
Silicon significantly increases the electrical resistivity of the steel, which decreases the induced eddy currents and narrows the hysteresis loop of the material, thus lowering the core loss
What is grain orientation?
Grain-oriented electrical steel usually has a silicon level of 3% (Si:11Fe). It is processed in such a way that the optimum properties are developed in the rolling direction, due to a tight control (proposed by Norman P. Goss) of the crystal orientation relative to the sheet. The magnetic flux density is increased by 30% in the coil rolling direction, although its magnetic saturation is decreased by 5%. It is used for the cores of power and distribution transformers, Cold Rolled Grain-oriented steel is often abbreviated to CRGO
What is core?
CRGO is usually supplied by the producing mills in coil form and it has to be cut into "laminations" which when stacked together to form a core, which is an integral part of any transformer. Grain-oriented steel is used in large power and distribution transformers, and certain audio output .
What is core loss?
It is the electrical power lost in terms of heat within the core of electrical equipment, when cores are subjected to AC magnetising force. It is composed of several types of losses - Hystereses loss, eddy current loss within individual Laminations and inter-laminar losses that may arise if Laminations are not sufficiently insulated from each other.
What is meant by M4, M3….
- American Iron and Steel Institute which gave the nomenclature for CGO materials with M as a prefix and a number following (eg. M4, M5, M6 etc.) M indicates magnetic material, and the number following approximately indicated 10 times the core loss of earliest CRGO material in watts per lb. at 1.5T and 60 cycles. Today however, this number is not relevant, but still denotes the accepted grade and popularly used throughout the world (e.g. M4 denoted magnetic material having core loss of approx.0.4W/lb at 1.5T/60Hz)
From where does KRYFS Import CRGO?
Japan , UK , U.S.A , Russia & Korea , in various grades of different permeability
What are the quality and testing methods used by KRYFS?
Our Stringent quality checks for improving efficiencies and product & process innovations. Our state of the art Brockhaus Laboratory enables KRYFS to have continuous R&D on CRGO from various mills. KRYFS has complete traceability of every job manufactured at it’s plants and tests each and every coil used for all electrical properties like core loss, permeability, insulation resistivity, coercivity etc. KRYFS also conducts independent research on advantages of Step Lap core over Non Step Lap core.