Austempering ductile iron (ADI) supercharged diesel engine six-cylinder crankshaft and production method

The invention belongs to the class of metal materials. After a supercharged technology is used for a diesel engine, the load born by a crankshaft is improved by 45-67 percent. The fatigue property of ordinary ball iron cannot meet the requirement of service and is replaced by alloy steel. The invention provides an austempering ductile iron (ADI) supercharged diesel engine six-cylinder crankshaft and a production method which both determine chemical constituents, particularly determine the addition of alloying elements, propose definite requirements on the percent of spheroidization and the number of graphite pebbles and also determine the parameter of an isothermal quenching process. After quenching, the deformation of the six-cylinder crankshaft is controlled within a certain range, which is a key measure of the method. A special heat treatment tire for quenching the six-cylinder crankshaft is designed so as to obtain a satisfactory result. The application of a crankshaft fillet rolling technology greatly improves the fatigue property of the six-cylinder crankshaft. The invention makes a pioneering contribution to manufacturing the supercharged diesel engine six-cylinder crankshaft by the ADI and greatly reduces the production cost of the six-cylinder crankshaft.