CN1324151C - Guipure furnace knitting needle brightness quench technics parameter determining method - Google Patents
Guipure furnace knitting needle brightness quench technics parameter determining method Download PDFInfo
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- CN1324151C CN1324151C CNB2004100179732A CN200410017973A CN1324151C CN 1324151 C CN1324151 C CN 1324151C CN B2004100179732 A CNB2004100179732 A CN B2004100179732A CN 200410017973 A CN200410017973 A CN 200410017973A CN 1324151 C CN1324151 C CN 1324151C
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Abstract
The present invention relates to a determining method of brightness quenching technique parameters of knitting needles in a mesh belt furnace, knitting needles which is densely arrayed on a mesh belt is regarded as a thin plate in a quenching process in the present invention, and is combined with the mesh belt into a whole with different thermal properties; a heat conduction equation with the heating characteristics of a mesh belt furnace is established, and analog computation is carried out by a computer via an interpolation method and a finite difference method to determine temperature field distribution in the quenching process of the knitting needles; the method can ensure that a temperature in a position in front of a flame curtain is lower than the oxidation decarbonization temperature of the knitting needles; the temperature of the knitting needles can reaches an expectant austenitizing temperature Tc in a furnace chamber; heat preservation time is reasonable. The technique parameters are reasonable technique parameters. The temperature change rule of the knitting needles in the mesh belt furnace in the quenching process can be known via the method, the technique parameters of the mesh belt furnace is determinated according to the method so as to quench the knitting needles; the method can ensure that the expectant mechanical properties of the knitting needles can be obtained after heat treatment is carried out; consequently, the mesh belt furnace is improved to make the quenching of the knitting needle is simple and reliable.
Description
Technical field:
The present invention is relevant with knitting needle, relates to the thermal treatment under the knitting needle continuous production condition, particularly a kind of method of determining Needle in Caterpillar Furnace bright quenching processing parameter with computer simulation.
Background technology:
Knitting needle is mainly used the high carbon steel manufacturing at present, in order to prevent the knitting needle surface oxidation and decarbonization takes place, and need heat-treat in vacuum or protective atmosphere.The major equipment that knitting needle quenches is a net belt type protective atmosphere resistance furnace; hereinafter to be referred as meshbeltfurnace; its quenching process can illustrate with Fig. 1: the bright quenching of knitting needle 2; it is cracking by organic substance; at the inner protective atmosphere 9 that forms of burner hearth; guarantee knitting needle 2 in heat-processed, catalytic oxidation atmosphere does not prevent to form oxide skin or surface decarburization.Meshbeltfurnace is a continuous production equipment, not the fixedly fire door of sealing.At the exit end of knitting needle 2, realize sealing by oil-quenching tank 8.At the inlet end of knitting needle 2, sealing is that the fiery curtain 4 that sealing function is arranged of formation is realized by the cracked gas burning.Several rows of knitting needle 2 dense arrangement are placed on the guipure 1 of movement continuously together, enter burner hearth with guipure 1 and are heated, and fall into oil groove 8 at last and quench.Meshbeltfurnace is divided into the independent temperature-controlled area section 5,6,7 of three sections equal lengths.The knitting needle thermal treatment process is the quenching of cracking protective atmosphere lightization, and main processing parameter can be divided into 4 classes: three sections burner hearth controlled temperature that the decision fire box temperature distributes; Cracking medium, cracking temperature and the consumption of decision furnace atmosphere; Determine knitting needle to heat up and the guipure speed or heat-up time of austenitization with fire box temperature; The quenchant kind and the temperature of decision knitting needle hardening capacity and quenching stress.
Definite method that above processing parameter is present mainly proposes by rule of thumb, carries out technological test then, revises repeatedly according to experimental result, makes the use properties of knitting needle reach requirement substantially, the processing parameter in definite production of comprehensively gathering together at last.This method is called the technology method of trial and error here.Owing to do not understand knitting needle variation of temperature rule in quenching process, the technology method of trial and error not only needs to carry out repeatedly technological test, and is difficult to find the processing parameter of optimum matching.Therefore, the processing parameter of Que Dinging and the knitting needle produced is difficult to the mechanical property that reaches best in this way.Because the heating of knitting needle and insulation by the comprehensive decision of various processing parameters, therefore, when local condition changes, make heat treated result become unstable.Actual investigation is found, the problem that domestic enterprise's ubiquity is such, and the consequence that causes is: the knitting needle quality of production is unstable and performance is on the low side.
Summary of the invention:
Technical problem to be solved by this invention is to overcome above-mentioned the deficiencies in the prior art, a kind of method of definite Quenching Process of Needle in Caterpillar Furnace parameter is provided, not only can understand knitting needle temperature changing regularity in the meshbeltfurnace quenching process by present method, and the meshbeltfurnace processing parameter of determining according to present method quenches to knitting needle, can guarantee to obtain after the knitting needle thermal treatment mechanical property of expectation, to the improvement of meshbeltfurnace, it is more easy to be reliable that knitting needle is quenched in view of the above.
Technical solution of the present invention is as follows:
A kind of method of definite Needle in Caterpillar Furnace bright quenching processing parameter, said processing parameter comprises that fiery curtain position, meshbeltfurnace controlled temperature, guipure speed, the preceding temperature of fiery curtain, pyrolyzer alcohol drip speed, quenchant and cooling temperature, is characterized in that the step of this method is as follows:
1.. according to the material and the use properties requirement of knitting needle, determine the quenching temperature scope, get intermediate value and make burner hearth controlled temperature T
k
2.. according to the target carbon potential, determine that a speed of pyrolyzer industrial spirit is 60～65 or 105～110 droplets/minute.
3.. according to knitting needle material austenitic transformation time t
1, austenite homogenizing soaking time t
2With the required burner hearth length L of material austenite homogenizing
2Determine guipure speed V:
V＝L
2/(t
1+t
2)；
4.. at above-mentioned T
kUnder the condition of V, measure the preliminary fiery curtain position L of meshbeltfurnace
1With fire box temperature distribution T (x);
5.. the knitting needle of quenching process dense arrangement on guipure is considered as thin plate, lumps together,, set up the heat-conduction equation that comprises meshbeltfurnace heating characteristics as the different integral body of hot rerum natura with guipure:
V(T/x)＝λ/ρCp[(
2T/x
2)+(
2T/y
2)+(
2T/z
2)]
Final condition is:
Fire door is a first kind final condition, and boundary temperature is the envrionment temperature of fire door, and this example is implemented in summer, gets room temperature T (0)=30 ℃;
Other is a third boundary condition, depends on fire box temperature distribution T (x), and guipure fire door intermediate point is a true origin,
In the formula:
T is the temperature of knitting needle point;
λ is the thermal conductivity of knitting needle material;
ρ is the density of knitting needle material;
Cp is the specific heat at constant pressure of knitting needle material;
The position that x, y, z are knitting needle point in fixing rectangular coordinate system; Adopt temperature field distribution T ' that method of interpolation and finite difference method calculate the knitting needle quenching process (x) with computer;
6.. calculation result T ' (x) is compared with the knitting needle heat-processed of expecting, guarantee that temperature is less than knitting needle oxidation and decarbonization temperature before fiery curtain position, knitting needle reaches the austenitizing temperature Tc of expectation in burner hearth, and rational soaking time is arranged, this processing parameter is reasonable technological parameter.
The preliminary fiery curtain of described meshbeltfurnace position is measured by ruler.
Described fire box temperature distributes and adopts XWX-1042 type self-balancing recorder to measure, and surveys with armouring nickel chromium triangle-Nickel-Silicom thermocouple.
The material of described knitting needle is the SK-5 steel, consult handbook as can be known its quenching temperature scope be 780～820 ℃, T
k=T
c+ (50～90 ℃), T
c=727 ℃, the oxidation and decarbonization temperature is 540～560 ℃, and corresponding quenching process parameters is determined as follows:
1.. burner hearth controlled temperature T
kIt is 800 ℃;
2.. fiery curtain position is from the distance L of stove gate
1=0.2m;
3.. temperature must be lower than 540 ℃ before the fiery curtain;
4.. a speed of pyrolyzer industrial spirit is 105～110 droplets/minute;
5.. guipure speed V=300mm/min, t
1=20 seconds, t
2=60 seconds;
6.. guipure burner hearth length L=L
1+ L
2=0.2m+V (t
1+ t
2)=0.6m.
Described meshbeltfurnace is the syllogic meshbeltfurnace, gets 790 ℃ near the controlled temperature of fire door inlet section, and the controlled temperature of stage casing and outlet section is got 800 ℃.
Described controlled temperature near the fire door inlet section is got and is lower than 540 ℃ temperature, and the controlled temperature of stage casing and outlet section is got 800 ℃, and corresponding guipure speed is lower than 300mm/min.
The improved meshbeltfurnace of the present invention is made up of four sections heating control sections, first section is near stove gate 0.2m heating control section on one side, its controlled temperature should be lower than 540 ℃, and it is 300 ℃ that this example is got controlled temperature, and back three sections controlled temperature is set at the quenching austenitizing temperature of knitting needle expectation.
The main technologic parameters of described meshbeltfurnace is:
The width made from SK5 is 1.4mm master's pin, and controlled temperature is 800 ℃, and it is 105～110/min that guipure speed 300mm/min, alcohol drip speed;
The jacquard needle width made from SK5 is 6mm, and controlled temperature is 805 ℃, guipure speed 160mm/min, and a speed of alcohol diluting soln is 60～65/min
The width made from 65Mn is the jacquard needle of 6mm, and controlled temperature is 825 ℃, and guipure speed is 160mm/min, and a speed of alcohol diluting soln is 60～65/min.
Technique effect of the present invention:
The present invention adopts computer mould to draw up knitting needle quenching process temperature field distribution in meshbeltfurnace, and knitting needle temperature changing regularity in meshbeltfurnace quenching heat-processed has been had detailed understanding.
On this basis,, determine the processing parameter that Needle in Caterpillar Furnace is quenched, relatively meet the objective law of quenching technology, be not easy to produce the problem of knitting needle unstable properties from the physical and chemical performance of knitting needle material.
The temperature of meshbeltfurnace is lower than knitting needle oxidation and decarbonization temperature before fiery curtain, guarantees that the knitting needle quenching process does not have oxidation and decarbonization and takes place.
According to the determined alcohol cracking of the target carbon potential amount of dripping is science, has guaranteed that carbon potential is reasonable within fiery curtain, can not make knitting needle embrittlement and decarburization.
Utilize processing parameter of the present invention, instruct knitting needle to quench, the actual result that obtains is: the knitting needle surface hardness is controlled at HV676～713, increase substantially, with the centre hardness basically identical, solved the insufficient problem of knitting needle surface hardness, other performance of knitting needle also all meets or exceeds the textile industry standard, be doubled than in the past work-ing life, reached 4～6 months.
By computer simulation, proposed existing meshbeltfurnace is improved: by means of the equipment of new texture, can rely on the control cracking medium amount of dripping controlled target carbon potential separately, rely on the expansion furnace temperature to guarantee that knitting needle was lower than the oxidation and decarbonization temperature before entering fiery curtain position, with final stage fire box temperature control knitting needle austenitizing temperature, rely on interlude fire box temperature and guipure speed control knitting needle austenitizing soaking time.Like this, can conveniently regulate separately each processing parameter that influences the knitting needle quenching.By existing thermal treatment theory and experience,, realize that easily optimal processing parameter cooperates to differing materials and difform knitting needle.It is highly beneficial to obtain best comprehensive mechanical property for knitting needle.
Description of drawings:
The present invention is further described below in conjunction with drawings and Examples.
Fig. 1 is existing syllogic knitting needle quenching meshbeltfurnace structural representation.
Fig. 2 is the flow sheet of Needle in Caterpillar Furnace quenching temperature field computer simulation.
Fig. 3 is that three sections burner hearth controlled temperature are 800 ℃, knitting needle temperature field numerical simulation result figure when guipure speed is 100mm/min.
Fig. 4 is that three sections burner hearth controlled temperature are 800 ℃, knitting needle temperature field numerical simulation result figure when guipure speed is 300mm/min.
Fig. 5 is that three sections burner hearth controlled temperature are 800 ℃, knitting needle temperature field numerical simulation result figure when guipure speed is 800mm/min.
Fig. 6 is knitting needle temperature field numerical simulation result figure when adopting former processing parameter.
Fig. 7 is a four-part form meshbeltfurnace structural representation of the present invention.
Embodiment:
Be that the Quenching Process of Needle of material is that the invention will be further described for embodiment with the SK-5 steel below.
1. cracking medium and consumption thereof determines
The bright quenching of knitting needle is the cracking by organic substance, at the inner protective atmosphere that forms of burner hearth, guarantees heat-treatment part in heat-processed, and catalytic oxidation atmosphere does not prevent to form oxide skin or surface decarburization.Meshbeltfurnace is a continuous production equipment, not the fixedly fire door of sealing.At the exit end of knitting needle, realize sealing by oil-quenching tank.At the inlet end of knitting needle, sealing is that the fiery curtain that sealing function is arranged of formation is realized by the cracked gas burning.
Present embodiment cracking medium adopts industrial spirit, splashes into pyrolyzer and carries out cracking, and the atmosphere of decomposition is led to meshbeltfurnace.The amount of dripping of alcohol has determined the carbon potential of stove inside: the amount of dripping is big, carbon potential height, knitting needle embrittlement; The amount of dripping is little, a little less than the carbon potential, even in fiery curtain inside, also may cause the knitting needle decarburization.
The foundation that the amount of dripping is determined is the target carbon potential.Can adopt carbon potential control meter directly to control, also can test definitely, can also calculate determine by air consumption with the iron foil measurement.Present embodiment calculates by air consumption, determines the meshbeltfurnace that 1.4m is long, treatment S K5 steel knitting needle, and the suitable alcohol amount of dripping is that 105-110 drips/min.
The position of fire curtain is relevant with the consumption of cracking medium, under the above alcohol amount of dripping condition, with the direct position of measuring the curtain that fires of steel ruler, is 0.2m apart from stove gate.
2. burner hearth heating controlled temperature and guipure speed determines
Determining of the controlled temperature of burner hearth heating and guipure speed plays an important role for the heat-processed of knitting needle.To a great extent, affect knitting needle before entering fiery curtain, whether reach the oxidation and decarbonization temperature.Simultaneously, also influence knitting needle austenitizing Heating temperature and soaking time.This problem must be taken all factors into consideration in conjunction with the temperature field numerical simulation of knitting needle heat-processed.
With reference to Fig. 1, to the heat-processed that knitting needle quenches, analyze from physical significance, mainly comprise following characteristics:
1) energy derive in knitting needle 2 heat-processedes comprises: with the convective heat exchange of burner hearth, the radiative transfer of furnace wall, and the thermal conduction by guipure between the drop-bottom.
2) knitting needle 2 closely forms a line, and constantly is transported to burner hearth inside by guipure 1, realizes continuous production.Like this, also there is thermal conduction between the knitting needle.
3) knitting needle changes in each position constantly, because the position difference, for single knitting needle, final condition is also constantly changing.
Because above characteristics,, all may run into unsurmountable difficulty if be basic any numerical evaluation in order to the thermal conduction differential equation.This difficulty be exactly single needle with respect to fixed coordinate system, its position constantly changes.Perhaps with respect to the identical moving coordinate system of guipure 1 translational speed, knitting needle 2 is at the final condition of guipure 1 travel direction, constantly changing in time.No matter use any system of coordinates, the interface between simulation knitting needle and the contiguous needles, its final condition all is difficult to obtain by engineering method.
The basis of the foundation of the thermal conduction differential equation is the Energy Analysis for High of cell cube.If ignore the thermal resistance of transmission of heat by contact and the latent heat of austenite phase transformation, just all knitting needles 2 on the guipure can be considered according to a thin plate, with the guipure 1 that moves, be used as successive, integrated solid material that performance is different is investigated.In fixed coordinate system, consider the characteristics of Needle in Caterpillar Furnace quenching heat-processed, set up the energy equation of this engineering problem, in other words mathematical model:
In the formula T[℃] be the temperature of certain point of knitting needle 2, with the position of knitting needle in burner hearth and this position in knitting needle relation is arranged; V[mm/min] be guipure speed, during continuous production a constant; λ [W/ (m ℃)] is the thermal conductivity of material; ρ [kg/m3] is the density of material; Cp[J/ (kg ℃)] be the specific heat at constant pressure of material.X, y, z point are in the fixing position of rectangular coordinates.
The research object that above equation comprises is exactly the sheet metal that inner all knitting needles 2 of meshbeltfurnace are formed, and with the guipure 1 of meshbeltfurnace inside, unites the different whole plate of hot rerum natura of formation.Owing to considered meshbeltfurnace quantity-produced characteristics, i.e. the stably manufactured of transient can be converted into final condition the border of this whole plate that can obtain on the engineering.
Under the requirement of satisfying engineering problem, can with near the final condition of the boundary element of fire door as first kind final condition, its temperature is:
T(i，j，k)＝T
0
T
0Be the envrionment temperature of stove gate knitting needle 2, present embodiment is got room temperature, is 30 ℃.
Other borderline unit can be considered the 3rd class final condition that satisfies on the thermal conduction study.It determines that method is to get envrionment temperature to distribute, and present embodiment is exactly that fire box temperature distributes and interface heat exchange coefficient.
It is XWX-1042 type self-balancing recorder that present embodiment carries out the used instrument of actual temperature measurement.What measure that the temperature of different positions in the burner hearth uses is that diameter is that the armouring nickel of 2mm is pressed against-Nickel-Silicom thermocouple.
The interfacial heat exchange of third boundary condition calculates with coefficient of heat transfer method usually, but the coefficient of heat transfer itself does not have clear physical meaning, and is not easy usually directly to determine.On the engineering, mainly adopt the whole bag of tricks to carry out actual measurement, perhaps adopt similarity principle to quote or estimate.This example adopts similarity principle to calculate, and method of calculation can be with reference to the theory or the achievement in research of thermal conduction study aspect.
3. the hot rerum natura of material is determined method, mainly is according to relevant handbook, perhaps directly tests obtaining by the method for some standard.But must consider that hot rerum natura is with variation of temperature.These routine knitting needle 2 materials are SK-5 (being equivalent to T9A) steel and 65Mn, and its performance can directly be found in relevant handbook.
After finishing above step, just can programme.Existing engineering software also can carry out proximate calculation, but must final condition reasonably be handled according to the physical characteristics of meshbeltfurnace.
Guipure 1 and knitting needle 2 are divided into the unit, and cell size depends on the computational accuracy requirement, and this example is 0.35mm * 0.35mm * 0.35mm.Fig. 2 is a Needle in Caterpillar Furnace quenching temperature Flow Field Numerical mimic flow sheet.The iterative calculation method that adopts is Gauss's iterative method, with FORTURN language establishment operation program.
The material that most of enterprise production knitting needle is used is the SK-5 steel, is equivalent to homemade T9A steel.The temperature range of the quenching heating of this material is 780-820 ℃, and the oxidation and decarbonization temperature is 540-560 ℃.For guaranteeing its best over-all properties, get 800 ℃ of its intermediate values here, as three sections burner hearth controlled temperature of meshbeltfurnace.For thoroughly avoiding oxidation and decarbonization, with its decarburization temperature with 540 ℃ as criterion.
At the burner hearth controlled temperature is that guipure speed can change under 800 ℃ of conditions.From the thermal conduction differential equation, the variation of guipure speed may influence the change of temperature field of knitting needle heating.Present embodiment supposes that respectively the speed of guipure is 100mm/min, and 300mm/min and 800mm/min carry out the temperature field numerical simulation of knitting needle quenching process.Analog result is seen Fig. 3, Fig. 4 and Fig. 5.
By Computer simulation results as can be seen, the trend of knitting needle temperature variation is near the distribution of fire box temperature.Generally by the controlled temperature decision of burner hearth, therefore, the controlled temperature of burner hearth has determined the heat-processed of knitting needle to the temperature distribution of burner hearth substantially.The difference of guipure speed has determined the position difference of knitting needle temperature near fire box temperature.Guipure speed is high more, and the knitting needle temperature is far away more from fire door near the fire box temperature position of meshbeltfurnace.Just knitting needle is near the fire door of meshbeltfurnace, and before fiery curtain position, its temperature is lower in other words.Therefore, single from solving the decarburization problem consideration on knitting needle surface, guipure speed is higher good.
Can also find that from analog result in the actual heat-processed, the internal temperature of knitting needle is also incomplete same, particularly near stove gate.Calculation result shows that the position, pin hook part of knitting needle is heated up the fastest, and knitting needle needle body intermediary bottom is heated up the slowest.This difference increases along with the increase of guipure speed, yet, with regard to the situation of stove gate, guipure speed high more, the temperature that reaches at burner hearth same position place of knitting needle is low more.For example, under the guipure velocity conditions of 800mm/min,, just reach the oxidation and decarbonization temperature at distance fire door 0.27m place even heat up the fastest position, pin hook part.And be under the condition of 100mm/min in guipure speed, even heat up the slowest knitting needle needle body intermediary bottom, just reached the oxidation and decarbonization temperature at distance fire door 0.18m place.
In sum, the even aspect of collateral security knitting needle temperature considers, guipure speed is slower, and good.From preventing that knitting needle oxidation and decarbonization aspect from considering, guipure speed is faster, and good.But from analog result, even under the condition of 800mm/min, the slowest position of knitting needle intensification has also reached the temperature that burner hearth is set.
The former processing parameter such as the table 1 of certain enterprise's knitting needle lightization quenching, the position of measuring its fiery curtain is 0.22m at the distance fire door.Use above step, it has been carried out the Temperature Field Simulation of knitting needle lightization quenching heat-processed, result such as Fig. 6.As seen from the figure, the knitting needle the fastest position, pin hook part of heating up has just reached the temperature of oxidation and decarbonization at distance fire door 0.13m, and the knitting needle the slowest position (knitting needle intermediary bottom) of heating up has also reached the oxidation and decarbonization temperature at distance fire door 0.16m place.Therefore, the inevitable oxidation and decarbonization of knitting needle.
The former quenching process parameters of table 1
| The knitting needle type | Grade of steel | Heating temperature ℃ | Cooling temperature ℃ | Heat-up time min | Cracking temperature ℃ | Ethanol drip speed (drip/min) | Guipure speed (mm/min) | Quenching machine oil | ||
| Entrance region | The intermediate zone | Outlet area | ||||||||
| Main pin | SK5 | 845 | 850 | 850 | 100 | ≥6 | 950 | 80～90 | ≤240 | 20# |
Knitting needle with former art breading has been carried out hardness measurement, represented the macrohardness of the core structure of knitting needle to meet or exceed HRC54, can reach the required standards.But the microhardness tester with 200g are measured, and surface hardness does not reach requirement (HV579) generally less than HV485 at all.Confirmed the conclusion that computer simulation obtains: the surface oxidation decarburization.In addition, the little further surface oxidation decarburization that has aggravated knitting needle of the alcohol amount of dripping.
Another problem that former technology exists is that austenitizing temperature is too high, and soaking time is long.This can not produce too much influence to surface hardness, but can reduce fatigue strength, plasticity and the toughness of the comprehensive mechanical property of knitting needle, particularly knitting needle, has a strong impact on knitting needle work-ing life.Metallographic structure analysis confirms that with the knitting needle of table 1 art breading, its heart portion has occurred carbide to a certain degree really and assembled, and the quantity of carbide reduces.In addition, the knitting needle life-span is also shorter, has only 1-3 month.These have further verified the analysis conclusion of computer simulation.
For the SK5 steel, reasonably austenitizing temperature should be Tc=727 ℃, and getting the austenitic transformation time is 20s, homogenizing soaking time 1min.By the quasi-definite 3 sections burner hearth holding temperatures of computer mould is 800 ℃, and guipure speed is 300mm/min.
Near the burner hearth of one section at meshbeltfurnace fire door, controlled temperature has reduced by 10 ℃, helps guaranteeing not oxidation and decarbonization.By way of compensation, the also corresponding reduction of the speed of guipure some, get 285mm/min.Comprehensive definite Quenching Process of Needle parameter such as table 2:
The Quenching Process of Needle parameter that table 2 numerical simulation and industrial analysis are determined
| The knitting needle type | Grade of steel | Heating temperature ℃ | Cooling temperature ℃ | Heat-up time min | Cracking temperature ℃ | Ethanol drip speed (drip/min) | Guipure speed (mm/min) | Quenching machine oil | ||
| Entrance region | The intermediate zone | Outlet area | ||||||||
| Main pin | SK5 | 790 | 800 | 800 | 100 | 5 | 950 | 105～110 | 285 | 20# |
The knitting needle of handling under this new processing condition can be seen by metallographic structure analysis, the knitting needle of handling under the novel process, and the carbide that heart portion has not had former technology to occur is assembled, and more there is not the deterioration of carbide morphology in the surface.Illustrate and solved the overheated of former technology and surface decarburization problem.
With new processing parameter, to carry out the light quenching of knitting needle, and carry out temper, the final properties parameter is listed in table 3.
The tissue and the performance of knitting needle after the final thermal treatment of table 3
| Needle body surface hardness (HV0.2) | Needle latch surface hardness (HV0.2) | Needle latch allows quiet pulling force (kg) |
| 653 | 517 | 2.9 |
| Knitting needle pull bending angle | Needle body surface/heart portion microstructure | Needle latch surface microstructure |
| 33.6° | Tempered martensite+moderate carbide (evenly) | Tempered martensite+carbide (elastoplasticity is better) |
Determine the processing parameter that knitting needle quenches under the existing meshbeltfurnace condition by computer simulation, can understand knitting needle heating process temperature Changing Pattern, according to the performance of knitting needle material and expectation, each processing parameter of science decision meshbeltfurnace.Compare with the existing processes method of trial and error, need not to carry out repetition test, and, the comprehensive mechanical property of knitting needle guaranteed easily.
Yet the heat-processed of knitting needle is subjected to the influence of burner hearth controlled temperature and guipure speed simultaneously.For the knitting needle of different varieties, its temperature-rise period is also inequality, must carry out repeated calculation machine simulation tentative calculation, just can find rational quenching technology.
The present invention has also attempted Processes and apparatus is improved, and can guarantee not oxidation and decarbonization of knitting needle, reaches the mechanical property of expectation simultaneously.
The improvement of technology is carried out in original syllogic meshbeltfurnace, if the controlled temperature of first section burner hearth is set at a certain temperature value less than 540 ℃, can guarantee that knitting needle is lower than the oxidation and decarbonization temperature before entering fiery curtain position.This example is got 500 ℃, but guipure speed must be reduced to 140mm/min, can guarantee the mechanical property after knitting needle quenches.This method is favourable for guaranteed performance, but has reduced production efficiency simultaneously.
Improvement to equipment can make technology controlling and process more simple and reliable, and the structure of improved meshbeltfurnace sees that Fig. 7 is on original Equipment Foundations, heats control section separately on one side add 0.2m at close stove gate.It is improved on three sections stoves, claims four sections heating meshbeltfurnaces.
Among the figure:
1-guipure 2-knitting needle
The burner hearth heating zone that 3-increases newly, length are 0.2m, and temperature is controlled at 300 ℃
Three sections control heating zone on 4- fire curtain 5,6, the original equipment of 7-, temperature is determined according to knitting needle material and performance requriements; 8-oil-quenching tank 9-protective atmosphere
Illustrate: do not have the other parts of change, do not draw in the drawings, for example, pyrolyzer, guipure running device, oil groove detailed structure and fire box temperature control device etc.
The first section burner hearth that increases, controlled temperature is set at a temperature value far below the surface oxidation decarburization temperature (540-560 ℃) of steel, for example, 300 ℃.Next three sections quenching austenitizing temperatures that are set at expectation, to the main pin made from the SK5 steel, controlled temperature is 800 ℃; To the jacquard needle made from the SK-5 steel, owing to require better toughness, temperature to be controlled to be 805 ℃, if make jacquard needle with 65Mn, controlled temperature should be at 825 ℃.Determine guipure speed according to the knitting needle size.Main pin width is 1.4mm, and guipure speed is 300mm/min; The jacquard needle width is 6mm, and guipure speed is 160mm/min.According to the performance of expectation, select the cracking medium and drip amount.For main pin, the cracking medium is an industrial spirit, drips amount 105-110 and drips/min; For jacquard needle, adopt the alcohol of dilution, the amount of dripping is dripped/min for 60-65.
Through equipment and technology adjustment, the present main pin of producing, the surface hardness basic controlling is at HV676-713, and the bending angle of pulling of knitting needle surpasses 60 degree.Through above new quenching technology resulting knitting needle, carry out corresponding tempering after, again through the insulation in later stage, deoil and after polishing etc. handles, obtain the knitting needle that novel process is produced.Through the detection of relevant department and the situation of the actual use of user, its result of appraisal are: through the knitting needle of new thermal treatment process production, its surface hardness increases substantially, with the centre hardness basically identical, solved the insufficient problem of knitting needle surface hardness, reached the textile industry specified standards fully, other performance index of knitting needle also all meet or exceed the standard of textile industry, be doubled than in the past work-ing life, reached 4-6 month.
The jacquard needle surface hardness is controlled to be HV630-670, and the bending angle of pulling of knitting needle surpasses 140 degree, has solved the fragility of bringing owing to the stress concentration that forms towards tooth fully.Be subjected to the welcome of Subscriber Unit.
Claims (7)
1, determines the method for Needle in Caterpillar Furnace bright quenching processing parameter, said processing parameter comprises that fiery curtain position, meshbeltfurnace controlled temperature, guipure speed, the preceding temperature of fiery curtain, pyrolyzer alcohol drip speed, quenchant and cooling temperature, is characterized in that the step of this method is as follows:
1.. according to the material and the use properties requirement of knitting needle, determine the quenching temperature scope, get intermediate value and make burner hearth controlled temperature T
k
2.. according to the target carbon potential, determine that a speed of pyrolyzer industrial spirit is 60～65 or 105～110 droplets/minute.
3.. according to knitting needle material austenitic transformation time t
1, austenite homogenizing soaking time t
2With the required burner hearth length L of material austenite homogenizing
2Determine guipure speed V:
V＝L
2/(t
1+t
2)；
4.. at above-mentioned T
kUnder the condition of V, measure the preliminary fiery curtain position L of meshbeltfurnace
1With fire box temperature distribution T (x);
5.. the knitting needle of quenching process dense arrangement on guipure is considered as thin plate, lumps together,, set up the heat-conduction equation that comprises meshbeltfurnace heating characteristics as the different integral body of hot rerum natura with guipure:
V(T/x)＝λ/ρCp[(
2T/x
2)+(
2T/y
2)+(
2T/z
2)]
Final condition is:
Fire door is a first kind final condition, depends on envrionment temperature;
Other is a third boundary condition, depends on fire box temperature distribution T (x), and guipure fire door intermediate point is a true origin,
In the formula:
T is the temperature of knitting needle point;
λ is the thermal conductivity of knitting needle material;
ρ is the density of knitting needle material;
Cp is the specific heat at constant pressure of knitting needle material;
The position that x, y, z are knitting needle point in fixing rectangular coordinate system; Adopt temperature field distribution T ' that method of interpolation and finite difference method calculate the knitting needle quenching process (x) with computer;
6.. calculation result T ' (x) is compared with the knitting needle heat-processed of expecting, guarantee that temperature is lower than knitting needle oxidation and decarbonization temperature before fiery curtain position, knitting needle reaches the austenitizing temperature Tc of expectation in burner hearth, and rational soaking time is arranged, this processing parameter is reasonable technological parameter.
2, the method for definite Needle in Caterpillar Furnace bright quenching processing parameter according to claim 1 is characterized in that: the preliminary fiery curtain of described meshbeltfurnace position is measured by ruler.
3, the method for definite Needle in Caterpillar Furnace bright quenching processing parameter according to claim 1, it is characterized in that: the material of described knitting needle is the SK-5 steel, consult handbook as can be known its quenching temperature scope be 780～820 ℃, T
k=T
c+ (50～90 ℃), T
c=727 ℃, the oxidation and decarbonization temperature is 540～560 ℃, and corresponding quenching process parameters is determined as follows:
1.. burner hearth controlled temperature T
kIt is 800 ℃;
2.. fiery curtain position is from the distance L of stove gate
1=0.2m;
3.. temperature must be lower than 540 ℃ before the fiery curtain;
4.. a speed of pyrolyzer industrial spirit is 105～110 droplets/minute;
5.. guipure speed V=300mm/min, t
1=20 seconds, t
2=60 seconds;
6.. guipure burner hearth length L=L
1+ L
2=0.2m+V (t
1+ t
2)=0.6m.
4, the method for definite Needle in Caterpillar Furnace bright quenching processing parameter according to claim 3 is characterized in that: described meshbeltfurnace is the syllogic meshbeltfurnace, gets 790 ℃ near the controlled temperature of fire door inlet section, and the controlled temperature of stage casing and outlet section is got 800 ℃.
5, the method for definite Needle in Caterpillar Furnace bright quenching processing parameter according to claim 3, it is characterized in that: the controlled temperature of close fire door inlet section is got and is lower than 540 ℃ temperature, the controlled temperature of stage casing and outlet section is got 800 ℃, and corresponding guipure speed is lower than 300mm/min.
6, the method for definite Needle in Caterpillar Furnace bright quenching processing parameter according to claim 1, it is characterized in that: this meshbeltfurnace is made up of four sections heating control sections, first section is near stove gate 0.2m heating control section on one side, its controlled temperature is lower than 540 ℃, and back three sections controlled temperature is set at the quenching austenitizing temperature of knitting needle expectation.
7, the method for definite Needle in Caterpillar Furnace bright quenching processing parameter according to claim 6, it is characterized in that: the main technologic parameters of described meshbeltfurnace is:
The width made from SK5 is 1.4mm master's pin, and controlled temperature is 800 ℃, and it is 105～110/min that guipure speed 300mm/min, alcohol drip speed;
The jacquard needle width made from SK5 is 6mm, and controlled temperature is 805 ℃, guipure speed 160mm/min, and a speed of alcohol diluting soln is 60～65/min
The width made from 65Mn is the jacquard needle of 6mm, and controlled temperature is 825 ℃, and guipure speed is 160mm/min, and a speed of alcohol diluting soln is 60～65/min.
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|---|---|---|---|
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| CN101633977B (en) * | 2009-05-08 | 2014-02-19 | 青岛优耐尔精密织针有限公司 | Method for vacuum hardening of knitting needle of circular knitting machine |
| CN108330269A (en) * | 2018-03-21 | 2018-07-27 | 浙江双鸟机械有限公司 | Chain hoist wheel workpiece continuous quenching device |
| CN114480801B (en) * | 2021-12-28 | 2023-12-08 | 石狮市汇星机械有限公司 | Method for batch processing knitting needles by heat treatment process |
| CN117904404A (en) * | 2023-12-12 | 2024-04-19 | 浙江芒锐机械设备有限公司 | Quenching equipment for knitting needle material |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1099806A (en) * | 1994-06-09 | 1995-03-08 | 田义德 | Low-carbon alloy steel nail for nailingun cement and jet nail and making method |
| JPH07256379A (en) * | 1993-11-01 | 1995-10-09 | Ethicon Inc | Manufacture of surgical needle |
| DE19919889A1 (en) * | 1998-05-01 | 2000-02-10 | Mani Inc | Surgical needle |
| CN1282639A (en) * | 1999-08-03 | 2001-02-07 | 风琴针株式会社 | Needls and manufacturing method thereof |
-
2004
- 2004-04-27 CN CNB2004100179732A patent/CN1324151C/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07256379A (en) * | 1993-11-01 | 1995-10-09 | Ethicon Inc | Manufacture of surgical needle |
| CN1099806A (en) * | 1994-06-09 | 1995-03-08 | 田义德 | Low-carbon alloy steel nail for nailingun cement and jet nail and making method |
| DE19919889A1 (en) * | 1998-05-01 | 2000-02-10 | Mani Inc | Surgical needle |
| CN1282639A (en) * | 1999-08-03 | 2001-02-07 | 风琴针株式会社 | Needls and manufacturing method thereof |
Non-Patent Citations (3)
| Title |
|---|
| 织针淬火加热过程中温度场的计算机模拟 费东晔 等，中国纺织大学学报，第26卷第2期 2000 * |
| 网代炉织针淬火工艺的研究 朱世根 等，中国纺织大学学报，第26卷第2期 2000 * |
| 网代炉织针淬火工艺的研究 朱世根 等，中国纺织大学学报，第26卷第2期 2000;织针淬火加热过程中温度场的计算机模拟 费东晔 等，中国纺织大学学报，第26卷第2期 2000 * |
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