To provide a piercer boring method of a hard-to-work material capable of preventing generation of inner flaw when performing the piercer boring of the hard-to-work material.
In the piercer boring method for manufacturing a seamless steel tube by rolling and boring a hard-to-work material by a piercer mill, the relationship between the material temperature and the hot deformation resistance ([MPa]) is expressed by formula (1), and relational formula (2) between the material temperature immediately before the boring (T[k]) and the material advancing speed during the boring (V[mm/sec]) when performing the piercer boring of the hard-to-work material is satisfied, preventing generation of inner flaw due to the overheat during the boring. [MPa]=Aexp(D/T[K])(d/dt)m ...(1), T[K]+(1+0.002V[mm/sec])K(T)T0 [K]...(2).
JPH05169110 | METHOD AND DEVICE FOR SKEW ROLLING |
JPH05309401 | SHAFT MATERIAL ROLLING MILL |
Next Patent: METHOD FOR MANUFACTURING MICRO PARTS