CN105714240A - Nitridation process for worm gear - Google Patents

Abstract

The invention discloses a nitridation process for a worm gear. The nitridation process is characterized by comprising the following steps: (1) clamping a to-be-nitrided worm gear on a special tool, hoisting the to-be-nitrided worm gear to a preheated cleaning pool for cleaning via a crane, then directly putting the cleaned to-be-nitrided worm gear into a preheating furnace with a temperature of 300 DEG C, carrying out preheating for 2 h, then heating the preheating furnace to 480 DEG C and carrying out preheating for 2 h; (2) carrying out nitridation which refers to filling of mixed gas consisting of ammonia gas and nitrogen and comprises two phases, wherein in the first phase, the worm gear is maintained at a temperature of 510 to 520 DEG C for 10 h and an ammonia decomposition rate is 18 to 25%, and in the second phase, the worm gear is maintained at a temperature of 510 to 520 DEG C for 10 h, the ammonia decomposition rate is 30 to 50% and cooling in furnace to 200 DEG C and air cooling out of the furnace are successively carried out; and (3) after completion of nitridation, hoisting the worm gear to a post-nitridation cleaning pool for cooling via the crane, then hoisting the worm gear to a hot-water cleaning pool for cleaning in 8 to 10 min, maintaining the worm gear in the hot-water cleaning pool for 10 min and then hoisting the worm gear in the air so as to allow the worm gear to be rapidly dried. The nitridation process is simple, omits a plurality of repeated procedures, improves work efficiency and enables the overall performance of the worm gear to be greatly improved.

Description

Turbine and worm nitriding process

Technical field

The present invention relates to a kind of turbine and worm nitriding process.

Background technology

Heat treatment nitrogenize be iron and steel under the temperature conditions of 520 DEG C～570 DEG C, nitrogenize and tufftride in ammonia+nitrogen or ammonia+methanol+nitrogen atmosphere.In recent years, nitrogenizing and on soft-nitriding process, having numerous embodiments: such as saying ammoniated gas after evacuation in advance or ammonia+methanol nitrogenation treatment technology；Also having in first coarse vacuum heating, afterpulse ammoniated gas carries out the technique such as nitrogenizing.Existing hard Nitriding Technology, the cycle is typically in 24～28 hours, and nitration case reaches 0.2～0.3mm, and in nitriding process, nitrogen gesture is wayward, owing to nitrogen gesture is too high and forms crisp phase, causes the hydraulic performance decline of machine components.

Summary of the invention

Because the drawbacks described above of prior art, the technical problem to be solved is to provide a kind of turbine and worm nitriding process, and this nitriding process is simple, eliminates a lot of repeatability operation, improves work efficiency so that workpiece various aspects of performance increases substantially.

For achieving the above object, the invention provides a kind of turbine and worm nitriding process, it is characterised in that comprise the steps:

(1) will turbine and worm clamping be nitrogenized on specific purpose tool, with driving winch to preheating service sink clean, be directly placed into preheating furnace after cleaning, preheating furnace temperature is 300 DEG C, preheat 2h；And then preheating furnace is warming up to 480 DEG C, preheat 2h；

(2) nitriding process is the mixing gas being filled with and including ammonia and nitrogen, point two stages, is incubated 10h, ammonia dissociation rate 18%-25% in the first stage at 510-520 DEG C；Second stage is incubated 10h, ammonia dissociation rate 30%-50% at 510-520 DEG C, cools to 200 DEG C of air coolings of coming out of the stove with the furnace；

(3) winching to driving after having nitrogenized and nitrogenize the cooling of rear service sink, winch to hot water service sink and clean, keep 10 minutes, then hang in atmosphere after 8-10 minute, turbine and worm workpiece dries rapidly.

The invention has the beneficial effects as follows: the nitriding process of the present invention is simple, eliminate a lot of repeatability operation, improve work efficiency so that workpiece various aspects of performance increases substantially.

Detailed description of the invention

Technical scheme disclosed by the invention is a kind of turbine and worm nitriding process, it is characterised in that comprise the steps:

(1) will turbine and worm clamping be nitrogenized on specific purpose tool, with driving winch to preheating service sink clean, be directly placed into preheating furnace after cleaning, preheating furnace temperature is 300 DEG C, preheat 2h；And then preheating furnace is warming up to 480 DEG C, preheat 2h；

(2) nitriding process is the mixing gas being filled with and including ammonia and nitrogen, point two stages, is incubated 10h, ammonia dissociation rate 18%-25% in the first stage at 510-520 DEG C；Second stage is incubated 10h, ammonia dissociation rate 30%-50% at 510-520 DEG C, cools to 200 DEG C of air coolings of coming out of the stove with the furnace；

(3) winching to driving after having nitrogenized and nitrogenize the cooling of rear service sink, winch to hot water service sink and clean, keep 10 minutes, then hang in atmosphere after 8-10 minute, turbine and worm workpiece dries rapidly.

The nitriding process of the present invention is simple, eliminates a lot of repeatability operation, improves work efficiency so that workpiece various aspects of performance increases substantially.

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 turbine and worm nitriding process, it is characterised in that comprise the steps:

(1) will turbine and worm clamping be nitrogenized on specific purpose tool, with driving winch to preheating service sink clean, be directly placed into preheating furnace after cleaning, preheating furnace temperature is 300 DEG C, preheat 2h；And then preheating furnace is warming up to 480 DEG C, preheat 2h；

(2) nitriding process is the mixing gas being filled with and including ammonia and nitrogen, point two stages, is incubated 10h, ammonia dissociation rate 18%-25% in the first stage at 510-520 DEG C；Second stage is incubated 10h, ammonia dissociation rate 30%-50% at 510-520 DEG C, cools to 200 DEG C of air coolings of coming out of the stove with the furnace；

(3) winching to driving after having nitrogenized and nitrogenize the cooling of rear service sink, winch to hot water service sink and clean, keep 10 minutes, then hang in atmosphere after 8-10 minute, turbine and worm workpiece dries rapidly.