CN105779734A - Heat treatment technology for boring rod - Google Patents

Abstract

The invention discloses a heat treatment technology for a boring rod. The heat treatment technology is characterized by comprising the following steps that 1, the technological process comprises the steps of blanking, rough turning, quenching and tempering, stress relief annealing, rough grinding, nitriding and fine grinding; and 2, according to the technological requirements, (1) quenching and tempering are conducted at (900-940) DEG C*3-5 h, after air cooling is conducted, high-temperature tempering is conducted at (620-640) DEG C*4-6 h, the stress relief annealing process is conducted at (550-600) DEG C*6-8 h, and the boring rod is subjected to furnace cooling to 300 DEG C, taken out of a furnace and subjected to air cooling; (2) nitriding is conducted, specifically, the nitriding temperature is 480 DEG-560 DEG, and the nitriding speed is 0.01-0.02 mm/h; and (3) several aspects need to be noticed, specifically, a, the ammonia decomposition rate temperature is predicted to be 480 DEG C, and heating up can be conducted only when the ammonia decomposition rate is smaller than 5% so that the effect that air in a furnace pot is completely exhausted can be ensured; b, when the decomposition rate is suddenly increased, whether water is accumulated in an exhaust pipe or not should be checked at first, then ammonia gas is added, and if necessary, a furnace cover can be opened; and c, after nitriding is finished, the boring rod is subjected to furnace cooling, the positive pressure in the furnace is kept to prevent a workpiece from being oxidized, and the tapping temperature is controlled to be lower than 250 DEG C.

Description

A kind of boring bar Technology for Heating Processing

Technical field

The present invention relates to a kind of boring bar Technology for Heating Processing.

Background technology

The vitals of boring machine is clang bar, and it bears the effect of frictional force in the course of the work, to bear bending, torsional moment simultaneously, and therefore its stress is complicated, is the exigent parts of technical conditions, must keep high powder degree and dimensional stability in work process.Summary of the invention

Because the drawbacks described above of prior art, the technical problem to be solved is to provide a kind of boring bar Technology for Heating Processing, and this process is simple, it is possible to increase the performance of boring bar each side, increases its service life, enhances the market competitiveness.

For achieving the above object, the invention provides a kind of boring bar Technology for Heating Processing, it is characterised in that comprise the steps, 1) technological process: blanking → rough turn → modified → stress relief annealing → corase grind → nitriding → fine grinding；

2) technological requirement: (1) modified is at (900-940) DEG C × 3-5h, carries out high tempering 620-640 DEG C × 4-6h after air cooling, stress relief annealing technique is (550-600) DEG C × 6-8h, cools to 300 DEG C of air coolings of coming out of the stove with the furnace；

(2) nitriding: nitriding temperature 480-560 DEG C, infiltration rate is 0.01-0.02mm/h；(3) note: the temperature 1. predicting ammonia dissociation rate is 480 DEG C, could heat up, to guarantee the air complete emptying in retort when only ammonia dissociation rate is less than 5%;

2. when resolution ratio increases suddenly, should first check in exhaustor with or without hydrops. secondly add the flow of ammonia, bell can be opened if necessary;

3. furnace cooling, the malleation in holding furnace are wanted in boring bar nitriding after terminating, and to prevent workpiece oxidized, additionally tapping temperature controls at 250 DEG C.

The invention has the beneficial effects as follows: present invention process method is simple, it is possible to increase the performance of boring bar each side, increase its service life, enhance the market competitiveness.

Detailed description of the invention

Technical scheme disclosed by the invention is a kind of boring bar Technology for Heating Processing, it is characterised in that comprise the steps, 1) technological process: blanking → rough turn → modified → stress relief annealing → corase grind → nitriding → fine grinding；

2) technological requirement: (1) modified is at (900-940) DEG C × 3-5h, carries out high tempering 620-640 DEG C × 4-6h after air cooling, stress relief annealing technique is (550-600) DEG C × 6-8h, cools to 300 DEG C of air coolings of coming out of the stove with the furnace；

(2) nitriding: nitriding temperature 480-560 DEG C, infiltration rate is 0.01-0.02mm/h；(3) note: the temperature 1. predicting ammonia dissociation rate is 480 DEG C, could heat up, to guarantee the air complete emptying in retort when only ammonia dissociation rate is less than 5%;

2. when resolution ratio increases suddenly, should first check in exhaustor with or without hydrops. secondly add the flow of ammonia, bell can be opened if necessary;

3. furnace cooling, the malleation in holding furnace are wanted in boring bar nitriding after terminating, and to prevent workpiece oxidized, additionally tapping temperature controls at 250 DEG C.

This process is simple, it is possible to increase the performance of boring bar each side, increases its service life, enhances the market competitiveness.

The preferred embodiment of the present invention described in detail above.Should be appreciated that those of ordinary skill in the art just can make many modifications and variations according to the design of the present invention without creative work.Therefore, all technical staff in the art, all should in the protection domain being defined in the patent claims under this invention's idea on the basis of existing technology by the available technical scheme of logical analysis, reasoning, or a limited experiment.

Claims (1)

1. a boring bar Technology for Heating Processing, it is characterised in that comprise the steps, 1) technological process: blanking → rough turn → modified → stress relief annealing → corase grind → nitriding → fine grinding；

2) technological requirement: (1) modified is at (900-940) DEG C × 3-5h, carries out high tempering 620-640 DEG C × 4-6h after air cooling, stress relief annealing technique is (550-600) DEG C × 6-8h, cools to 300 DEG C of air coolings of coming out of the stove with the furnace；

(2) nitriding: nitriding temperature 480-560 DEG C, infiltration rate is 0.01-0.02mm/h；(3) note: the temperature 1. predicting ammonia dissociation rate is 480 DEG C, could heat up, to guarantee the air complete emptying in retort when only ammonia dissociation rate is less than 5%;

2. when resolution ratio increases suddenly, should first check in exhaustor with or without hydrops. secondly add the flow of ammonia, bell can be opened if necessary;

3. furnace cooling, the malleation in holding furnace are wanted in boring bar nitriding after terminating, and to prevent workpiece oxidized, additionally tapping temperature controls at 250 DEG C.