Near-isothermal hot spin forming method and heat complementing method for metal workpiece

A near-isothermal hot spin forming method for a metal workpiece, comprising steps of:

• heating a blank to a spin preheating temperature;
• transferring and clamping the heated blank on a workbench rotating with a main shaft of a spinning device, wherein a heat complementing system is mounted on a periphery of the workbench, and the blank is located in an effective heat complementing zone provided by the heat complementing system;
• measuring a blank temperature of the blank after clamping and fixing, and judging whether the blank temperature Tblank meets a pre-spinning temperature Tb spinning of the blank required by a near-isothermal hot spinning process;
• if Tblank≥Tb spinning, starting the spinning device to perform spinning;
• and if Tblank<Tb spinning, heating and temperature complementing the blank by the heat complementing system until Tblank≥Tb spinning is satisfied, and then starting the spinning device to perform spinning;
• and
• applying the near-isothermal hot spinning process in the spinning device to spinning form the blank;
• wherein during the near isothermal hot spinning process, the blank is actively heated and temperature complemented by the heat complementing system, and a spinning temperature is monitored in a spinning deformation zone of the blank in real time to ensure that a fluctuation range of the spinning temperature does not exceed ±20° C. from the beginning of a spinning deformation to the end.