CN102191451B - Double-hearth continuous rare earth carburizing equipment and process thereof - Google Patents
Double-hearth continuous rare earth carburizing equipment and process thereof Download PDFInfo
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- CN102191451B CN102191451B CN 201110097217 CN201110097217A CN102191451B CN 102191451 B CN102191451 B CN 102191451B CN 201110097217 CN201110097217 CN 201110097217 CN 201110097217 A CN201110097217 A CN 201110097217A CN 102191451 B CN102191451 B CN 102191451B
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Abstract
The invention discloses a process of a double-hearth continuous rare earth carburizing equipment. A through type continuous rare earth carburizing furnace comprises double hearths which are arranged in a Z shape, wherein a first hearth is a carburizing speed control hearth and is divided into I, II and III zones; and a second hearth is a carburized layer structure control hearth and is divided into IV and V zones. The two hearths are communicated or partitioned through a gate, and a material tray in the III zone is pushed to the IV zone by utilizing a transverse material-pushing mechanism. Operation parameters of basic processes of the zones are that: in the first hearth, the temperature of the zone I is 860 to 880 DEG C, and Cp is uncontrolled; the temperature of the zone II is 920 DEG C, and Cp is 1.20-1.25 percent; and the temperature of the zone III is 930 DEG C, and Cp is 1.30 to 1.4 percent; in the second hearth, the temperature of the zone IV is 880 to 890 DEG C, and the Cp is 1.1 to 1.2 percent; and the temperature of the zone V is 860 to 840 DEG C, and Cp is 0.9 to 1.0 percent. The carbon potential control accuracy of furnace gas is improved and the mutual interference is reduced, so the setting and adjustment of process parameters are simpler and easier, and the stability and reliability of process operation are greatly improved. By the process, the carburizing cycle is further shortened, and the work efficiency is improved by over 30 percent; moreover, the optimal metallographic structure is easy to obtain, so that the service life of a product is prolonged.
Description
Technical field:
The present invention relates to the continuous rare earth carburizing process of a kind of twin furnace formula.
Background technology:
In order to produce the thermo-chemical treatment of gear etc. in enormous quantities, heat treatment process enterprise generally all adopts the through gas carbruizing furance production of working continuously.Workpiece is contained on charging tray, and charging tray is arranged in order to discharge end by feed end, for example 30 minutes, 45 minutes or 60 minutes at regular intervals, by transfer bar mechanism, charging tray is pushed forward.Workpiece carries out carburizing in stove, decide the time in pusher cycle by charging tray number and depth of penetration and carburizing speed.Press stepped start-stop system pusher mode to discharge end.Can quench after coming out of the stove.Need to press and taken out on charging tray by mechanical manipulator when quenching, the continous way carburizing flow production line schematic block diagram that tradition adopts as shown in Figure 1.Production line is comprised of pre-oxidation furnace, continous way gas carbruizing furance, oil-quenching tank, mechanical manipulator, Quenching press etc.Workpiece on charging tray flows by push-and-pull material mechanical means and the operation of electrical control equipment automatic or manual.
Cementing furnace is divided into 5 districts that work alone by the carburization process process, and it is different that each distinguishes function,
Because the I-V district is all the burner hearth of a perforation, between each district, partition wall can not be set, the continuous propelling of blocking-up charging tray.This has just caused Carbon Potential Inside Furnace phase mutual interference between two zones, and in burner hearth, the weary gas of part carburizing needs to be burnt by former and later two venting port discharge points, in order to avoid pollute.This just causes respectively distinguishes carbon potential Cp and is difficult to accurate control.It is very low by IV, V two district Cp set(ting)values that more harmful is, must squeeze into air after the gas that the III district has a higher carbon gesture Cp flows into and Cp could be down to lower set(ting)value, this just causes carburized surface to form the black tissue, its hardness is down to standard Schwellenwert HRC58 or lower, cause this gear to produce premature wear and fatigure failure, the life-span declines to a great extent.
In order to overcome Carbon Potential Inside Furnace phase mutual interference between the through gas carbruizing furance of working continuously existing zone, the weary gas of burner hearth middle part carburizing needs to be burnt by former and later two venting port discharge points, in order to avoid pollute, each is distinguished carbon potential Cp and is difficult to accurate control, carburized surface forms the black tissue, cause this workpiece to produce premature wear and fatigure failure, the life-span decline to a great extent etc. problem we invented the continuous rare earth carburizing process of twin furnace formula.
Summary of the invention:
In order to achieve the above object, the technical solution used in the present invention is:
The continuous rare earth carburizing process of a kind of twin furnace formula is built into through re carburizing continuous oven burner hearth the twin furnace that is the zig-zag type arrangement, and the first burner hearth is that carburizing speed is controlled burner hearth, and the second burner hearth is that diffusion layer organization is controlled burner hearth.
The first burner hearth is divided into I, II, III district, and the second burner hearth is divided into IV, V district, by gate UNICOM or partition, utilizes horizontal pusher to push the charging tray in III district to the IV district between two burner hearths.
The basic technology characteristic parameter that each district adopts is as follows:
The first burner hearth: I district: 860--880 ℃, Cp is not controlled, the II district: 920 ℃ of XCp1.20-1.25%; III district: 930 ℃ of XCp1.30-1.4%;
The second burner hearth: IV district: 880-890 ℃ of XCp1.1-1.2%; V district: 860-840 ℃ XCp0.9-1.0%.
Pusher cycle: 25--27 minute.
Its feed end of the first burner hearth is connected with pre-oxidation furnace, and its discharge end of the second burner hearth is connected with Quenching press with mechanize oil-quenching tank and mechanical manipulator.Communicate by gate between two burner hearths, another effect of gate is the furnace gas partition with two burner hearths, so that according to function needs adjustment temperature and carbon potential separately.
The advantage of the continuous rare earth carburizing process of a kind of twin furnace formula of the present invention is
1, carburizing speed is significantly improved
Compare with west industrial state tradition carburization process, can improve carburizing speed more than 30%, compare with domestic, can improve carburizing speed 20～30%.When rare earth and carbon ooze altogether, not only make the penetration enhancer decomposition rate fast, purify workpiece surface, increase the solid gas interface speed of response, thereby make active atoms of carbon [C] diffusion coefficient D improve 50%.The technique pusher cycle is shortened, improved production efficiency, the saving energy, lowering energy consumption and reducing pollutants discharge effect is very remarkable.
2, changing processing condition makes diffusion layer organization better, performance and life-span significantly improve through large quantity research and production application to be proved, use the continuous rare earth carburizing process of twin furnace formula, strictly operate according to the listed process conditions of the present invention, cut off by the furnace gas of gate with two burner hearths, so that according to function needs adjustment temperature and carbon potential separately.Due to independent separately, need not adopt the fan the air method of gas of conventional carburizing to carry out for the adjustment of IV, V district carbon potential, thereby avoid producing the black tissue that is harmful to.And can accurately control temperature and the carbon potential in IV, V district.In order to produce the optimization carburized structure of re carburizing standard, that is: infiltration layer hypereutectoid district particularly surface carbonation thing K be the small and dispersed particulate state; Its matrix is the ultra-fine martensite of cryptocrystal shape; Hypereutectoid, eutectoid and hypoeutectoid district respectively account for 1/3.In the hypereutectoid district of infiltration layer austenite matrix with the equal Precipitation small and dispersed granular carbide K simultaneously of crystal boundary, thereby avoided former traditional technology only along crystal boundary particularly the triangle crystal boundary separate out defective thick carbide K.Make the carburizing top layer obtain small and dispersed carbide K, greatly improved surface hardness and the wear resistance of load-carrying vehicle drive axle gear pair, avoid because of the too low caused premature wear of surface hardness, fatigue lifetime short this great key issue.The performance strength and toughness synchronously improves, and greatly improves fatigue resistance and the supporting capacity of workpiece, will surpass the west Product Level work-ing life that make workpiece.
3, improved the carbon potential control precision of furnace gas, reduced the phase mutual interference, made the setting of processing parameter and adjustment become easily simple, the Stability and dependability of process operation improves greatly.The carburizing cycle is further shortened, improve work efficiency and can reach 30%, and easily obtain best microstructure, thereby guaranteed that product reaches best level work-ing life.
Fig. 1 continuous acieration furnace workpiece carbonization quenching schema
The continuous rare-earth carburizing furnace structure diagram of Fig. 2 twin furnace formula and processing parameter
Description of drawings:
The continuous rare earth carburizing process of a kind of twin furnace formula is built into through re carburizing continuous oven burner hearth the twin furnace that is the zig-zag type arrangement, and the first burner hearth is that carburizing speed is controlled burner hearth, and the second burner hearth is that diffusion layer organization is controlled burner hearth.Pass through gate UNICOM or partition between two burner hearths.
The first burner hearth is divided into I, II, III district, and the second burner hearth is divided into IV, V district, utilizes horizontal pusher to push the charging tray in III district to the IV district.The the second former IV of burner hearth district charging tray is pushed the V district to, and V district charging tray is released the processing after the second burner hearth carries out carburizing.Gate cuts off the first burner hearth and the second burner hearth.Utilize vertical pusher to push new charging tray and former I, II district charging tray to I, II, III district.According to function needs adjustment temperature and carbon potential separately, carry out carburizing by the processing parameter of respectively distinguishing of determining.After reaching specific time, open the sluices the first burner hearth and the second burner hearth UNICOM, utilize horizontal pusher to push the charging tray in III district to the IV district.So repeat, realize operate continuously.
Embodiment:
The basic technology characteristic parameter that each district adopts is as follows:
The first burner hearth: I district: 860--880 ℃, Cp is not controlled; II district: 920 ℃ of XCp1.20-1.25%; III district: 930 ℃ of XCp1.30-1.4%;
The second burner hearth: IV district: 880--890 ℃ of XCp1.1-1.2%; V district: 860--840 ℃ XCp0.9-1.0%.
Pusher cycle: 25--27 minute.
Application example 1: there is a double continous way gas carbruizing furance of 50Kw push-down in Harbin City company, stone or metal plate for standing a stove on as a precaution against fire size * mm, and the dish number is 24 * 2 totally 48, adopts n-formyl sarcolysine alcohol as protection gas, propane is carburetted gas, axle gear after the professional treatment bogie.This stove and conventional double gas carbruizing furance are identical, and just the charging tray number is slightly many, increase to 48 dishes by 44 dishes, and temperature, the carbon potential of former technique are allocated as follows:
The I district: 820 ℃, II district: 910 ℃ * Cp0.70%; III district: 930 ℃ * Cp1.15%; IV district: 900 ℃ * Cp1.0%; V district: 860 ℃ * Cp0.80%.
Process bogie back axle M475 spiral basin corner gear, the pusher cycle: 37 minutes, gear layer depth: 1.80-1.90mm.Metallographic structure: carbide K 0-2 level; Martensite M, paralympic A ' are all in the 3-5 level; Black is organized 25--35 μ m.
After adopting re carburizing, adopted high temperature high carbon potential carburizing technique.The basic technology parameter is as follows:
The I district: 860 ℃, II district: 920 ℃ * Cp1.150%; III district: 930 ℃ * Cp1.30%; IV district: 900 ℃ * Cp1.15%; V district: 860 ℃ * Cp1.0%.The pusher cycle: 30 minutes; Depth of penetration is 1.90-2.00mm.More former technique shortens 7 minutes pusher cycles, improves work efficiency 23%; And metallographic structure has clear improvement.The black tissue of product≤15 μ m, carbide K≤3 grade, martensite M, paralympic A ' are down to 3 grades by former 3-5 level, and obvious thinning effect is arranged.Because straight-flow furnace is respectively distinguished the mutual interference of Cp phase, wish obtains very difficulty of best microstructure debugging, only can reach under the strict technology operation.
Application example 2: with the same unit of application example 1, press the continuous re carburizing equipment of twin furnace formula and processing requirement thereof, due to I, II, III district as the first burner hearth, the main high carbon potential of high temperature that adopts is specifically designed to the raising infiltration rate, and carbon potential Cp easily accurately controls, thereby can be follow-up IV, V district tissue and debug and lay good basis.IV, V district is formed the second burner hearth, specially diffusion layer organization is controlled, because carbon potential Cp controls accurately, not disturbed by other factors, can easy to doly debug, can obtain best microstructure, and can steady in a long-termly produce.
The basic technology parameter that adopts is as follows:
The first burner hearth: I district: 860--880 ℃, Cp is not controlled the II district: 920 ℃ * Cp1.20-1.25%; III district: 930 ℃ * Cp1.30-1.4%;
The second burner hearth: IV district: 880--890 ℃ * Cp1.1-1.2%; V district: 860--840 ℃ * Cp0.9-1.0%.
Pusher cycle: 25--27 minute; Depth of penetration is 1.85-2.20mm.
Metallographic structure: black tissue: nothing, hypereutectoid+eutectoid layer depth accounts for total infiltration layer 70%.Hypereutectoid district carbide is the small and dispersed particulate state and distributes, extexine maximum particle size diameter is less than or equal to 1 μ m, and the carbide rank can be adjustable in 0-3 level scope, and Martensite is observed under 400 power microscopes and is the cryptocrystal shape, is hardenite or ultra-fine martensite under 800 times.Surface hardness HRC63-64; Due to structure refinement and super-refinement, less paralympic and dispersity is high, be difficult for differentiating.
This shows the invention of the continuous re carburizing equipment of twin furnace formula and technique thereof, improved the carbon potential control precision of furnace gas, reduced the phase mutual interference, make the setting of processing parameter and adjustment become easily simple, the Stability and dependability of process operation improves greatly.The carburizing cycle is further shortened, improve work efficiency and can reach 30%, and easily obtain best microstructure, thereby guaranteed that product reaches best level work-ing life.
Claims (1)
1. continuous rare earth carburizing process of twin furnace formula, it is characterized in that: re carburizing continuous oven burner hearth is built into the twin furnace that is the zig-zag type arrangement, the first burner hearth is that carburizing speed is controlled burner hearth, be divided into I, II, III district, the second burner hearth is that diffusion layer organization is controlled burner hearth, be divided into IV, V district, by gate UNICOM or partition, utilize horizontal pusher to push the charging tray in III district to the IV district between two burner hearths; Basic technology characteristic parameter that each district adopts is as follows: the first burner hearth: the I district: 860--880 ℃, Cp is not controlled; II district: 920 ℃ * Cp1.20-1.25%; The III district: 930 ℃ * Cp1.30-1.40%, the second burner hearth: IV district: 880--890 ℃ * Cp1.1-1.2%; V district: 860--840 ℃ * Cp0.9-1.0%; Pusher cycle: 25--27 minute.
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| CN 201110097217 CN102191451B (en) | 2011-04-19 | 2011-04-19 | Double-hearth continuous rare earth carburizing equipment and process thereof |
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| CN102191451B true CN102191451B (en) | 2013-06-19 |
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| CN102373399B (en) * | 2011-10-25 | 2013-07-10 | 哈尔滨汇隆汽车箱桥有限公司 | Lorry spiral bevel gear double-row rare earth continuous gas carburization heat treatment equipment |
| CN102373403B (en) * | 2011-10-25 | 2013-07-10 | 哈尔滨汇隆汽车箱桥有限公司 | Two-row rare earth continuous gas carburization furnace carburization medium flow rate disc |
| CN115369352A (en) * | 2022-08-24 | 2022-11-22 | 湖北三环汽车方向机有限公司 | Continuous furnace carburizing process |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN85107934A (en) * | 1984-11-13 | 1986-07-09 | 伊普森国际工业股份有限公司 | The method and the equipment thereof that adopt continuous furnace that metal works is heat-treated |
| CN1560318A (en) * | 2004-03-04 | 2005-01-05 | 上海交通大学 | Apparatus of dynamic testing controlling for carbon potential of vacuum furnace |
| JP2005049091A (en) * | 2004-09-08 | 2005-02-24 | Dowa Mining Co Ltd | Surface reforming heat treatment device for metallic material |
| CN101078037A (en) * | 2007-06-27 | 2007-11-28 | 吴江市天地人真空炉业有限公司 | Double-chamber low-pressure high flow rate vacuum quenching acetylene carburizing furnace |
| EP1980641A2 (en) * | 2007-04-02 | 2008-10-15 | Seco/Warwick S.A. | Method and measurement for the control of an active charge surface in the low pressure carburizing process |
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2011
- 2011-04-19 CN CN 201110097217 patent/CN102191451B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN85107934A (en) * | 1984-11-13 | 1986-07-09 | 伊普森国际工业股份有限公司 | The method and the equipment thereof that adopt continuous furnace that metal works is heat-treated |
| CN1560318A (en) * | 2004-03-04 | 2005-01-05 | 上海交通大学 | Apparatus of dynamic testing controlling for carbon potential of vacuum furnace |
| JP2005049091A (en) * | 2004-09-08 | 2005-02-24 | Dowa Mining Co Ltd | Surface reforming heat treatment device for metallic material |
| EP1980641A2 (en) * | 2007-04-02 | 2008-10-15 | Seco/Warwick S.A. | Method and measurement for the control of an active charge surface in the low pressure carburizing process |
| CN101078037A (en) * | 2007-06-27 | 2007-11-28 | 吴江市天地人真空炉业有限公司 | Double-chamber low-pressure high flow rate vacuum quenching acetylene carburizing furnace |
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