Being the steel for high intensity hammering which is used for the steel for high intensity hammering and the production

摘要

PROBLEM TO BE SOLVED: To provide inexpensive high strength steel for forging which has low contents of expensive alloy elements, particularly of Ni, has high strength and is useful e.g. as stock for a large crankshaft of a marine vessel.;SOLUTION: The high strength steel for forging has a composition in which the content of Ni is, by mass, ≤0.7%, also containing at least one kind of element selected from the groups consisting of V, Nb and Ta by 0.03 to 0.35% in total and 30 to 250 ppm N, and further satisfying the relation in the following inequality (1), and has a structure essentially consisting of bainite and martensite. The steel for forging is particularly useful as the stock for a large crankshaft. [the total (mass%) of V, Nb and Ta]+0.001×solid solution N (ppm)≥0.068...(1).;COPYRIGHT: (C)2002,JPO