Forging carbon-manganese steel - micro-alloyed with vanadium or niobium and cooling in air at room temp.

摘要

Steel forgings, esp. used as crankshafts for vehicle engines, are produced by forging a C-Mn steel contg. =0.2% C, micro-alloyed with 0.05-0.15% V or Nb, and contg. no further alloying components, at 900-1280 degrees C with V addn. or at 1250-1280 degrees C with Nb addn., followed by cooling the forgings, esp. individually, in air at = room temp. Micro-alloying additives improve yield strength but do not alter tensile strength. Re-heating after cooling is obviated; a pearlite structure is formed and forgings can be machined with tools used for forgings of heat-treatable steels.