Austenitic Stainless Steel are probably the most important under this group is that containing 15 to 20 percent chromium and 7 to 10 per cent nickel. A steel containing 18 per cent chromium and 8 per cent nickel is very widely used and is commonly referred to as 18/8 stainless steels. Such a steel may be readily cold - worked so that the hardness and tensile strength are markedly increased and wire may be produced by cold working. Owing to the high ductility , The steel lends itself readily to manipulate and fabrication, and is used extensively for the production of pressings. The steel is readily weldable after welding, it is susceptible to corrosive attack in an arc adjacent to the weld. Additions of molybdenum are made to certain grades to increase their corrosion resistance, whilst others have titanium or niobium added to stabilize the carbon. They cannot be hardened by heat treatment. Austenite in these steels is stable at all service temperatures. Austenite stainless steels are non - magnetic
Electrical Comparators are used as a means of detecting and amplifying small movements of a work contacting elements. An electrical comparator consists essentially of a pick-up head or transducer for converting a displacement into a corresponding change in current and a meter or recorder connected in the circuit to indicate the electrical change, calibrated to show in terms of displacement. Generally, an amplifier is needed to provide the requisite sensitivity and to match the characteristics of different parts of the circuit. Electrical comparators can be classified according to the electrical principle used in the pick-up head. Most of the comparators use either a differential transformer, an inductance bridge, a strain gauge or a capacitor as a means of detecting movement of the gauging element. There are different types of electrical comparators. One kind called an electrolimit gauge is used to check or measure the outside diameter of a roll. The objec...
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