1. A vacuum carbonitriding method comprising:
performing a vacuum carburizing process on an object to be treated in a heat treating furnace under reduced pressures by supplying a carburizing gas into the furnace that has been heated to a predetermined carburizing temperature;
performing a diffusing process on the object to be treated by stopping supply of the carburizing gas while keeping the carburizing temperature so as to diffuse carbon in the object to be treated under reduced pressures for a predetermined period of time based on the intended effective case depth; and
performing a nitriding process on the object to be treated by supplying a nitriding gas into the furnace under reduced pressures after lowering the furnace temperature.
2. The vacuum carbonitriding method according to claim 1, comprising:
using a mixed gas of ethylene gas and hydrogen gas as the carburizing gas.
3. The vacuum carbonitriding method according to claim 1 or 2, comprising:
controlling effective case depth of the object to be treated after quenching, which is performed following the nitridation, on the basis of a nitriding time.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of calculating a correction value for a machine tool having two or more translational axes and one or more rotational axes to correct an error in position or position and posture of a tool with respect to an object to be machined, which results from a geometrical error, in the machine tool, comprising a step of:
calculating a correction value for each of the translational axes using a command position of each of the rotational axes, a coordinate value of a correction reference point as one point designated in advance in a command position space of each of the translational axes, and a geometric parameter representing the geometrical error.
2. The method of calculating the correction value for the machine tool according to claim 1, wherein
the correction value for each of the translational axes is calculated also using a command position of each of the translational axes to which the coordinate value of the correction reference point is assigned.
3. The method of calculating the correction value for the machine tool according to claim 1, wherein
the correction reference point moves in accordance with the command position of each of the rotational axes.
4. The method of calculating the correction value for the machine tool according to claim 2, wherein
the correction reference point moves in accordance with the command position of each of the rotational axes.
5. A program for calculating a correction value for a machine tool, which is designed to cause a computer to carry out the method of calculating the correction value for the machine tool according to claim 1.
6. A program for calculating a correction value for a machine tool, which is designed to cause a computer to carry out the method of calculating the correction value for the machine tool according to claim 2.
7. A program for calculating a correction value for a machine tool, which is designed to cause a computer to carry out the method of calculating the correction value for the machine tool according to claim 3.
8. A program for calculating a correction value for a machine tool, which is designed to cause a computer to carry out the method of calculating the correction value for the machine tool according to claim 4.