The role of thermal treatment is to improve the material performance of the steel pipe and precision steel pipes, eliminate residual stress, and improve the cutting processing performance of steel pipe metals. According to different purposes, thermal treatment process can be divided into two categories: preparing heat treatment and final thermal treatment.
The purpose of preparing heat treatment is to improve processing performance, eliminate internal stress, and prepare good gold -phase tissue for final thermal treatment. Its thermal treatment technology includes annealing, positive fire, timeliness, and quality adjustment.
(1) Antuction and positive fire
Antuction and positive fire are used to rough through heat processing. Carbon steel and alloy steel with a carbon content greater than 0.5%. In order to reduce its hardness and easy cutting, annealing treatment is often used; carbon -containing carbon steel and alloy steel with less than 0.5%, to avoid the knife when the hardness is too low. And use positive fire treatment. The annealing and torch can still refine the grains and uniformly organize it to prepare for future thermal treatment. Antuction and fire are often arranged after rough manufacturing and before rough processing.
(2) Time processing
The time processing is mainly used to eliminate the internal stress generated in rough manufacturing and mechanical processing.
In order to avoid excessive transportation workloads, for parts with general accuracy, it can be arranged once before refinement processing. However, parts with higher accuracy (such as the box of the benchmarking bed, etc.) should be arranged twice or the timeliness processing process twice or several times. Simple parts generally do not have timely processing.
In addition to the casting, for some precision parts (such as precision screws) with poor rigidity, in order to eliminate the internal stress generated in processing, stabilize the processing accuracy of the parts, and often arrange multiple timeliness between rough processing and semi -precision processing. Some axis parts are processed, and timely processing must be arranged after the school direct process.
(3) Restamination
The quality adjustment means that high temperature recovery treatment is performed after quenching. It can obtain a uniform and detailed recovery cable -generated tissue, which is prepared for subsequent surface quenching and nitrogen seepage treatment. Therefore, the quality adjustment can also be used as preparation of heat treatment.
Because the comprehensive mechanical properties of the parts are good, parts that require high hardness and abrasion -resistant parts can also be used as the final thermal treatment process.
