Drop forging of HSLA steel with application of thermomechanical treatment

Problems of realization of thermomechanical treatment for microalloyed-steel forgings are presented. The issue is discussed on the example of high-pressure-pump crankshaft. On the strength of numerical analysis results conditions for favourable strain and temperature distribution were determined. In addition, by means of numerical modelling proper perform geometry was designed, which allowed elimination of costly trials in industrial conditions, necessary especially for this part due to inclination to fold formation. The knowledge of precipitation kinetics in the analysed steel in combination with the obtained profiles of temperature made it possible to determine appropriate forging temperature, time, rate and a scheme of cooling. The experimental tests run in industrial conditions confirmed reasonability of assumed technology. Mechanical testing proved required high ultimate strength and yield stress and ductility.