The  φ350  mm  heavy  forging products  of  17-4PH precipitation  hardening  stainless  steel  were produced by EAF-VOD  process  melting  and  pig  iron  mold  bottom  casting  φ320  mm  electrode  of  17-4PH  steel(≤0.04C

16.20~  16.50Cr

4.50~4.70Ni

3.30～3.40Cu

0.25～0.40Nb)

then remelted  to 2.5 t(φ510～550mm)ESR  ingot and forged by 800 t hydraulic press or 5 t steam hammer. The process practice showed that it was available to avoid cracking of  the  steel  after  forging  by  controlling  end  forging  temperature(steam  hammer  980  ℃;hydraulic  press   1050℃)

soaking  forged   φ350   mm    17-4PH   steel   products   in   cover-type   furnace(1130~1150℃)

then   slow cooling   to(1050±10)℃   and  soaking

  fumnace  cooling  to  420℃

and  in  time  annealing  at  650℃.