Metal Cutting Machine A machine that uses a cutting method to machine metal blanks into machine parts. It is a machine that builds machines. We customarily call them machine tools. In China's machine tool industry, the size of machine tools is different, and the number of production is different. For medium and small-sized machine tools, mass production is generally used: large and heavy machine tools are produced in single or small batches. General machine tool parts conditions such as load, impact and lubrication conditions are significantly better than cars, tractors and heavy machinery.
The part is the support of the whole machine tool, and its precision maintainability is very demanding. Therefore, this article focuses on the characteristics of the heat treatment of the bed parts, roughly boils down to the following points:
(1) The use of steel for general use of non-alloy (carbon) structural steel and alloy structural steel. A few parts, such as inlaid steel rails, hardened screws, etc., use low-alloy tool steel and bearing steel.
(2) The salt bath furnace is used for non-oxidizing heating of most parts of the cycle-type furnace. Vacuum furnace or kerosene drip in a gas carburizing furnace to create a protective atmosphere.
(3) Partially hardened and surface hardened parts There are many machine tool parts that only require high wear resistance on the part of the surface. Except that a few parts are partially hardened by a salt bath furnace, most of the parts use local surface quenching methods (such as Induction heating, laser heating, ultrasonic heating, etc.) Hardening.
(4) Precision parts require high dimensional stability Usually, one or more stabilization treatments are often arranged in the process, such as stress relief annealing, low-temperature aging treatment, and cold treatment, to minimize the residual internal stress and ensure high dimensional stability. Sex.
(5) Widely used low-temperature chemical heat treatment machine tool parts are mostly designed from the perspective of rigid, heat treatment requirements become smaller, high wear resistance and good dimensional stability. Therefore, nitriding, nitrocarburizing and other low-temperature chemical heat treatment process has been widely used.
(6) Most steel parts must undergo pre-heat treatment such as castings, forgings, and rolled materials. They must be pre-treated by annealing, normalizing, or tempering to increase their strength, eliminate defects in the structure, and improve processing performance. : At the same time, prepare the organization for the final heat treatment to reduce heat treatment distortion.
December 23, 2021