CN102220472A - Heat treatment method of ultra-large bearing ring - Google Patents

Abstract

The invention relates to a heat treatment method of an ultra-large bearing ring, which comprises the step of quenching treatment: heating to 800-830 DEG C according to the effective thickness of the ultra-large bearing ring made of GCr15SiMn steel, keeping the temperature for 0.7-1.0 minute per millimeter of the effective thickness, then quenching in ZHY-101 quenching liquid, cooling to 50-120 DEG C, taking out of the quenching liquid and air-cooling to a room temperature; and heating to 180-250 DEG C for quenching and keeping the temperature for 6-12 hours. According to the heat treatment method, as water-based quenching is adopted, the mechanical properties are significantly better than those of oil quenching, the hardness and the uniformity of the hardness of the ultra-large bearing ring are improved greatly, and the insufficient quenching hardness of a rolling path and an inner diameter in traditional oil quenching is overcome. A water base is used for replacing an oil product, the consumption amount of the water base is significantly lower than the consumption amount of oil, the water-based quenching time is short, electrical energy is saved, and the water-based quenching liquid costs lower than the oil, so that the heat treatment cost of a bearing is greatly reduced. By adopting the heat treatment method, oil smoke, harmful volatile matters and fire hidden trouble can be avoided during the water-based quenching process.

Description

A kind of heat treating method of super large type bearing ring

Technical field

The present invention relates to the bearing parts heat treating method, particularly relate to a kind of heat treating method of GCr15SiMn steel super large type bearing ring.

Background technology

The fine or not key of bearing quality is the thermal treatment of bearing parts, and quenching is one of basic technology of thermal treatment.Super large type bearing ring adopted oil to quench as heat-eliminating medium always in the past.Adopt oil-quenched heat treating method that very long history is arranged, but exist several defectives that are difficult to overcome:

1, cooling power a little less than, super-huge lasso difficult quality after oil quenching that net thickness is bigger reaches the requirement of industry standard JB/T1255 fully, and has position hardness phenomenons on the low side such as raceway, internal diameter.

2, the oil smoke severe contamination air that produces in the quenching process cleans Residual oil and also brings liquid pollutent.

3, be prone to fire failure, dangerous.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of no obnoxious flavour, and is free from environmental pollution, no fire hazard, and cost is low, the heat treating method of energy-saving and cost-reducing super large type bearing ring.

The technical scheme that adopts is:

A kind of heat treating method of super large type bearing ring comprises:

Quench treatment: according to the net thickness of GCr15SiMn steel super large type bearing ring, when being heated to 800 ~ 830 ℃, with the insulation of every millimeter net thickness after 0.7 ~ 1.0 minute, in ZHY-101 hardening liquid (water-based quenching medium that Dalian three gold medal lubricating oil company limiteds produce), quench, be cooled to 50 ~ 120 ℃, go out the hardening liquid air cooling to room temperature.

Temper: the super large type bearing ring after the quench treatment is heated to 180 ~ 250 ℃ tempering, tempering insulation 6 ~ 12 hours.

The present invention is applicable to the quenching of super large type bearing ring, after the high-carbon-chromium bearing steel part heats as stated above, adopts the ZHY-101 water-based quenching medium to cool off, and obtains microstructure, hardness that complete conformance with standard requires, and better penetration of hardness.Adopt the present invention, the microstructure that obtains all is 2-3 grades of very good martensitic stuctures, and hardness all satisfies standard-required.The penetration of hardness of big wall thickness GCr15SiMn steel is also significantly greater than oil-quenched penetration of hardness.The present invention can significantly improve the GCr15SiMn super large type bearing ring thermal treatment quality of relatively thick, makes it to reach fully the industry standard requirement, and these are that traditional oil quenching processing method is beyond one's reach.

Simultaneously, the present invention significantly improves the supporting capacity of bearing parts.

The invention has the beneficial effects as follows:

1, the present invention adopts water base quenching technology, and water base quenching significantly is better than oil quenching on thermal treatment quality, the mechanical property, and can reach industry standard JB/T1255 requirement fully on the thermal treatment quality.Through professional mechanical performance index test, water base quenching technology significantly is better than oil quenching technology on bearing load.Simultaneously, water base quenching technology can significantly improve the hardness and the uniformity of hardness of super large type bearing ring, problems such as position quenching hardness deficiency such as raceway, internal diameter then often appear in traditional oil quenching technology, and especially for the bigger product of width dimensions, this problem is more outstanding.

2, water base quenching technology is saved cost significantly.Comprise two aspects: with water for oil, save power consumption.With water base replacement oil product, water-based hardening liquid per ton is than low 2,500.00 yuan of oil price lattice per ton, and water base consumption significantly is less than the consumption of oil; The reduction of the Heating temperature of part, time shorten in the water base quenching technology, have saved power consumption, and these all greatly reduce bearing thermal treatment cost.

3, more environmental protection is safer.Do not have oil smoke in the water base quenching process, no unwanted volatile has been stopped atmospheric pollution, has not also had the danger of fire fully.

Embodiment

Embodiment 1

Bearing specification 232/530CAK30/W33/YB5 outer ring, GCr15SiMn outside dimension 980.8mm width 356.4mm, outer internal diameter is 827mm, outer raceway S φ 900mm, net thickness 58mm, weight 401kg.

Heat treatment process specification: heating installation is the RJJ--160 stove, 1/stove of batch, Heating temperature to 805 ℃, soaking time 41 minutes (heat insulating coefficient 0.7 minute/millimeter), adopt after heating finishes in the ZHY-101 efficient inorganic polymer water-based quenching medium and quench, and string is moving in water-based quenching medium is cooled to 80 ℃, and water outlet is chilled to room temperature.200 ℃ of tempering after the quench treatment are incubated 6 hours.

Quality examination result after the thermal treatment:

After the quenching, raceway hardness HRC62-more than the 64(JB/T1255 standard-required HRC60).

Raceway hardness HRC60--61(JB/T1255 standard-required HRC56--61 after the tempering).

Microstructure: 3 grades of martensitic stuctures, no troostite in the 3mm of top layer (troostite is 1-5 grades in 1-5 grades of the JB/T1255 standard-required martensites, top layer 3mm).

Embodiment 2

Bearing specification 232/500CA/YF inner ring, material GCr15SiMn, the basic size situation is: outside dimension 642 mm, width are 300mm, net thickness 56 mm, weight 229kg.

Heat treatment process specification: heating installation is the RJX-75 stove, and 2 of batches, the Heating temperature of employing are 810 ℃, soaking time 42 minutes (heat insulating coefficient 0.75 minute/mm), total 170 minutes heat-up times, be as the criterion to guarantee soaking time.Adopt after heating finishes in the ZHY-101 efficient inorganic polymer water-based quenching medium and quench, and the moving cooling of string in water-based quenching medium, afterwards at 200 ℃ of tempering 7h.

Quality examination result after the thermal treatment:

Quench, raceway hardness HRC60--61(JB/T1255 standard-required HRC57--63 after the tempering).

Microstructure: 3 grades of martensitic stuctures, no troostite in the 3mm of top layer (1-5 grades of troostites are qualified in 1-5 grades of the JB/T1255 standard-required martensites, top layer 3mm).

Claims (1)

1. the heat treating method of a super large type bearing ring is characterized in that comprising:

Quench treatment: according to the net thickness of GCr15SiMn steel super large type bearing ring, when being heated to 800 ~ 830 ℃, after 0.7 ~ 1.0 minute, in the ZHY-101 hardening liquid, quench, be cooled to 50 ~ 120 ℃, go out the hardening liquid air cooling to room temperature with every millimeter net thickness insulation;

Temper: the super large type bearing ring after the quench treatment is heated to 180 ~ 250 ℃ tempering, tempering insulation 6 ~ 12 hours.

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