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
Steam Pressure at inlet to a steam turbine is reduced by throttling process to maintain the speed of the turbine constant at part load and hence this method of governing is called "Throttle Governing". Construction : Throttle governing system consists of a centrifugal governor, a lever , an oil pump , a pilot piston , control valve , a relay piston and a throttle valve. The throttle valve is moved by a relay piston. The relay piston is actuated by pilot piston control valve. There are two piston valves covering ports in the pilot piston control valve without any overlap. These piston valves are operated by lubricating oil supplied by a gear pump at 2 to 4 bar. The oil returns to the drain from this chamber. Working : When the turbine works on full rated load, the throttle valve will remain open. When the load is decreased, the energy output of the turbine becomes in excess and the turbine shaft speed increases. Hence, governor sleeve will lift. The upward movement of the
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