Background technology
Comprehensive mechanical coal mining has been popularized, and drag conveyor is Development of Continuous Transport System tool, is that colliery usage amount is maximum, is consumed most
Many visual plants.Drag conveyor is made up of head afterbody, intermediate channel and its appurtenances.Wherein, intermediate channel is that scraper plate is defeated
The important component of the bearer connection body of machine is sent, is the critical component of complete equipment, positioned at the middle part of scrapper conveyor, it is both to scrape
The running track of plate chain, is the walking track of coal-winning machine again, still carries the operation passage of coal stream.It is also simultaneously to be used on scrapper conveyor
Amount is maximum, quality most heavy part, and a general drag conveyor contains 100 more piece intermediate channels, and it is 1.2 meters or 1.5 often to save flute length
Rice.Intermediate channel is overall cast welding sealing bottom type structure, and intermediate channel is mainly by baffle, shovel board ledge and middle plate, bottom plate welding group
Into middle plate, bottom plate material are NM400, and baffle, shovel board ledge material are ZG30MnSi.Upper groove is used as Coal Transport, lower groove
Used for scraper plate return.
The national annual intermediate channel failed by abrasion reaches hundreds thousand of sections.
Its reason is:1. operation and middle plate, the abrasion of ledge of scraper plate, chain, coal stream, while in use, if meeting big
In the stuck groove of lump coal rock, middle plate, which is pressurized, can also produce buckling deformation;2. coal-winning machine is moved along intermediate channel ledge, causes ledge
Upper wear, while additional load and roller cut the impact in coal seam, can also cause ledge to deform;3. coal-winning machine advances to coal
The movement of wall direction produces horizontal direction bending, while plate is occurred arch curved for push-and-pull hydraulic support stress, in addition bottom plate
Bent above and below the uneven generation of laying, and then the press-bending of connector tension is bent, has aggravated middle plate, the abrasion at ledge edge.
It can be seen that, intermediate channel applying working condition is more severe, and stress is complicated and changeable, therefore it is required that intermediate channel have enough intensity, just
Degree and wearability.Big margin design is often used in order to meet in intensity requirement, reality, the wasting of resources is easily caused.And product
Quality be mainly reflected in mechanical property, so intermediate channel ledge should have good mechanical property.According to rough Statistics, China
The casting ledge weight that major Mei Ji factories produce every year is in more than 30Wt, and therefore, urgent need develops a set of more preferable manufacturing process,
To improve drag conveyor capability and performance.
Product current technology:
The ledge shape and structure of intermediate channel is complicated, and volume is larger, and machining is all relatively difficult, therefore straight using raw material
Connect casting.Steel-casting, which is easily produced, organizes extremely uneven after more serious dendritic segregation, solidification, especially alloy cast steel part
It is particularly evident.During solidification of molten steel, austenite grows up to different grain shapes along section thickness direction.Casting section is got over
Thickness, that is, when cooling down slower, column crystal and thick equiax crystal more reach.Column crystal and thick equiax crystal can reduce the mechanical property of steel,
Particularly toughness.Ledge wall unevenness is even, and often there are different institutional frameworks at each position of same casting, and remains quite big
Internal stress, thus its mechanical performance is poor.Research in the same industry to ZG30MnSi ledges in this respect is not a lot, is
The performance quality of ZG30MnSi chute steels is improved, it is necessary to carry out the linguistic term of this respect so that material composition and heat treatment
Influence to ZG30MnSi ledge steel qualities is reduced to minimum, and mechanical property reaches most preferably.
The content of the invention
Quality more preferably scraper plate can be obtained it is an object of the invention to the shortcoming for overcoming prior art there is provided one kind to convey
The technology of machine.
To achieve the above object, the technical solution used in the present invention is as follows:
The present invention provides a kind of coal face scraper conveyor intermediate channel manufacture craft, including casting step, heat treatment
Step, welding step.
Wherein described casting step is:
(1) selects 100 parts of 70 sand, and 7-8 parts of waterglass is fabricated to intermediate channel ledge mold, and makes mold water content be 5-
6%, wet pressing power is more than 0.008MPa, and penetrable ventilated to be more than 200, dry strength is more than 0.3MPa;
(2) makes molten steel tapping temperature be 1620-1640 DEG C, carries out calmness 5-10 minutes after tapping in steel ladle,
(3) starts to be poured into intermediate channel ledge mold, and makes molten steel keeping temperature be 1560-1580 in casting process
DEG C, start control low discharge cast during cast, then pour into a mould flow by increasing;Natural cooling form removal in 8 hours after casting complete;Will
The big intermediate channel ledge shaping structures after machining of intermediate channel ledge hair of cast molding;
Wherein described heat treatment step is:
(1) normalizings:The intermediate channel ledge of shaping structures is placed in heating medium, by 100-120 DEG C/h of speed
Progress is heated to 630-680 DEG C, and in this temperature range inside holding 1.5-2 hours;Heated again by 50 DEG C/h of speed
To 870-890 DEG C, and in this temperature range inside holding 4-6 hours;
(2) is cooled down:Stop heating, naturally cool to≤400 DEG C, and in this temperature range inside holding 5-7 hours;
(3) is tempered:The intermediate channel ledge that heating arrangement is molded again, firing rate is carried out by 100-120 DEG C/h, and
It is heated to 570-600 DEG C, and in this temperature range inside holding 5-6 hours;
Finally cool down:Stop being cooled to less than 300 DEG C in heating, stove, then naturally cool to room temperature;
Middle plate, bottom plate is are welded on ledge by wherein described welding step, and its process is as follows:
(1) is not less than 10 DEG C indoor in room temperature and welded;
(2) is preheated in advance to weld part, and makes heat input be 14-17KJ/cm, is uniformly added using cutting torch neutral flame
Each 30mm in hot weld interface both sides is wide, and middle plate is preheated to 150-200 degree, and ledge is preheated to 200-250 degree, then starts welding;
(3) after welding, intermediate channel is subjected to the welding stress annealing that disappears:Intermediate channel is heated to 500-550 DEG C, and keeps 5
Hour, then natural cooling.
A kind of coal face scraper conveyor intermediate channel ledge manufacture craft as described above, be specially:Described casting
Make in step, when pour steel is raised to mold rising head, cast 5 minutes should be stopped, then pouring into a mould rapidly again and pour full rising head.
A kind of coal face scraper conveyor intermediate channel ledge manufacture craft as described above, be specially:Molten steel is tapped
Temperature is 1630 DEG C, carries out calmness 7 minutes after tapping in steel ladle;It is 1570 DEG C to make molten steel keeping temperature in casting process.
A kind of coal face scraper conveyor intermediate channel manufacture craft as described above, be specially:Described welding step
It is rapid specific as follows:First ledge is stood up in both sides, middle plate is assembled in ledge waist, bottom plate is assembled in ledge bottom;When its is assembled,
The width of rebate of formation increases deformation-compensated amount △ B, is specially:Upper notch compensation rate △ B are 3-4mm, lower notch compensation rate △ B
For 4-5mm, and upper notch compensation rate △ B are less than lower notch compensation rate △ B2-3mm.
A kind of coal face scraper conveyor intermediate channel manufacture craft as described above, be specially:Described heat treatment
Step is:
(1) is heated:The intermediate channel that structure welding is molded is carried out being heated to 500-550 DEG C by 110 DEG C/h of speed;
(2) Stress relieving annealings:It is furnace-cooled to 150-200 DEG C and naturally cools to room temperature.
A kind of coal face scraper conveyor intermediate channel manufacture craft as described above, be specially:By middle part after welding
Groove carries out Stress relieving annealing:Intermediate channel is heated into 500-550 DEG C to be annealed.
Beneficial effects of the present invention are:
The distinctive mechanical structure feature of technology combination drag conveyor and use environment of the present invention, makes on scraper plate
The manufacturing process of conveyer, can effectively improve the wear-resisting mechanical performance of the middle pan of scraper conveyor, and obtain physical dimension essence
Du Genggao drag conveyor.
Embodiment
To make the object, technical solutions and advantages of the present invention clearer, below in conjunction with the specific embodiment of the invention and
Technical solution of the present invention is clearly and completely described corresponding accompanying drawing.
Refer to the attached drawing 1, intermediate channel is welded to form by ledge 1, middle plate 2, bottom plate 3, and middle plate 2, the material of bottom plate 3 are NM400, groove
It is ZG30MnSi to help 1, shovel side material, and main 30~70mm of wall thickness, two ends and middle part have thick big position.
Low-alloy cast steel of the ZG30MnSi chute steels based on carbon, manganese, the big element of silicon three, except this also has upper described lack
Measure impurity element.Carbon is the basic element for determining steel performance, is to obtain one of high intensity, efficient hardening element of high rigidity,
The mechanical strength and hardness of steel will change with the change of phosphorus content.Manganese is the element of weaker formation carbide, can be solid-solution in
Ferrite, so that reinforced ferrite.Manganese can strengthen the stability of austenite, and reduction quenching critical cooling rate improves quenching for steel
Permeability.But manganese plays the role of to promote crystal grain to grow up, the overheat to steel is more sensitive, and the higher temper fragility containing manganese is more apparent.
Silicon can be solid-solution in ferrite, and have stronger solution strengthening effect, while it has inhibition to tempering transition.When silicomanganese element
The proportioning of addition is where appropriate, the decarburization shortcoming caused by silicon can be reduced, while can reduce the overheat tendency of manganese steel.Aluminium is used as deoxidation
Agent is added, and aluminium can refine the crystal grain of steel, suppresses the timeliness of mild steel, improves the toughness of steel at low temperature, inoxidizability, wear-resisting
Property and fatigue strength.Because low-alloy cast steel requires higher to raw material, impurity element sulphur, phosphorus are often considered to be harmful member
Element, content must be controlled strictly.For the requirement of intermediate channel chute steel performance, the applicant changes the current ZG30MnSi of inspection repeatedly
Ledge steel sample, gained chemical composition content such as following table.
In chute steel actual production process, when correspondence sample is tested, it may appear that chemical composition proportioning is suitably conformed to
Ask, larger situation but occurs differing in mechanical performance after same heat treatment.A drag conveyor is needed in more piece simultaneously
, such as there is above-mentioned situation in portion's groove, and the intermediate channel performance difference that same scrapper conveyor can be caused different is larger, and whole of influence is scraped
The performance of trigger.So must the relation of chemically composition and mechanical performance adjust chemical composition proportion relation, due to
It is difficult the change of the wherein a certain element of control in actual production to realize the control to required performance.Therefore, various members are found
Element plays the comprehensive function of various elements to the affecting laws of mechanical property, the various chemical element contents of optimum proportioning, can either
So that material obtains preferable mechanical property, and easily implement in actual production.It must select reasonably to be heat-treated work simultaneously
Skill, improves the mechanical property and performance of chute steel to greatest extent.
According to above-mentioned condition, process is produced by below in this example design.
First, casting step:
The real modeling of use.Foudry line contracting interest rate is 2.0% by the selection of waterglass limestone sand, the reserved processing of machined surface
Surplus is 5mm, and to reduce casting weight, pattern draft machined surface uses increase and decrease wall thickness using casting section thickness, non-processing face is reduced
Mode, pattern draft be α/mm≤2.0mm.In lower loam core to ensure that loam core is non-rising, stud need to be used to carry out loam core
It is fixed.Cast uses bottom pouring type pouring.
Two kinds of materials of quartz sand and 70 sand, CO2 hardening are have selected in trial-production.Facing sand can be used in batch production process
Quartz sand, floor sand uses 70 sand.
Mulling is carried out using simpson mill.Because limestone sand is resistance to, stone roller property is poor, it is desirable to the muller of puddle mixer and chassis
Distance is 20-25mm, and scraper plate is 5-10mm with chassis distance.First dry-mixed 2-4 minutes, add water glass and carry out mixed grind.Molding sand
It see the table below with when performance:
Twice of zirconium English bauxite composite coating of mould surface flow coat.Because limestone sand produces decomposition at high temperature, generation is big
The gas of amount, will carry out exhaust on sand mold during moulding, improve sand mold exhaust capacity.
According to material requirements, chemical element, particularly P, S, the control of Al content must be strictly controlled in smelting process.Adopt
Poured into a mould with shaking ladle, and band is with stove sample, to carry out mechanical test and chemical element selective examination.
To make casting obtain good feeding, the control of molten steel tapping temperature is after 1620-1640 DEG C, tapping in steel ladle
Calm to carrying out molten steel, so as to be suspended in the inclusion floating in molten steel, the calm time should be greater than 5min according to tapping temperature, no
More than 10min.Pouring temperature is controlled at 1560-1580 DEG C, and cast cold can reduce inclining for the defects such as casting shrinkage cavity and porosity
To.Poring rate is controlled during cast, during beginning molten steel flow is controlled smaller, it is to avoid molten steel washes away to sand mold, then
It is gradually increased.When molten steel rises to rising head, beam should be delayed, then increase beam and continue to pour into a mould, until pouring full rising head.It is anti-
Only the clinker in molten steel enters sand mold die cavity.Whole casting process does not allow molten steel to stop, it is to avoid casting produces cold shut defect.Pour
Add thermal-insulating covering agent after note on casting pressing port, improve riser feeding effect.Shake out time is controlled not less than 8 hours, is prevented
The too early shake out of casting is deformed.
During production ledge part, often occur occurring the glassy Slag inclusion of local celadon at the top of ledge.This folder
Slag thing float from molten steel, because top does not set rising head, Slag inclusion can not be discharged, and be just detained and formed dreg defect.
The main constituent of Slag inclusion is manganese aluminosilicate, and CaO content is very low, and Slag inclusion is not directly from reduced blast furnace,
Because reduced blast furnace has very high calcium oxide content, general tall and big 30%-50%.Containing very high MnO in Slag inclusion, so with
Molten steel is relevant, because containing a large amount of manganese elements in molten steel.SiO in MnO and reducing slag in molten steel2、Al2O3Deng acid or weak acid
Property oxide reaction product.Due to molten steel in casting ladle calm limited time, the manganese aluminosilicate slag inclusion being involved in molten steel without
Method floats completely, and part slag liquid enters die cavity with molten steel in casting process, floats at the top of casting mold, forms cast(ing) surface slag inclusion
Thing.Rear manganese addition iron is formed by strengthening reduction initial stage and the preceding molten steel precipitation desoxydation of tapping, thin slag, it is possible to reduce MnO in molten steel
Content and elimination casting manganese aluminosilicate Slag inclusion, eliminate this defect.
2nd, Technology for Heating Processing:
The change phase point of cast steel is to formulate the important evidence of Technology for Heating Processing, because ZG30MnSi ledge carbons content of steel are higher,
And it is complex-shaped, the heat treatment process of normalizing+tempering is used to it.
Each procedure in heating-up temperature, soaking time and the whole heat treatment process of the type of cooling of steel is joint effect heat
Result.In complicated heat treatment process, the change of a little of a certain procedure all influences ZG30MnSi chute steels to obtain
Different mechanical properties.Therefore, it is many-sided common work to the Effect on Mechanical Properties of steel for chemical Composition Control and heat treatment
Every one of technique must be paid much attention in result, production process, to obtain the ZG30MnSi chute steels of more high-quality.
Described heat treatment step is:
(1) normalizings:The intermediate channel ledge of shaping structures is placed in heating medium, by 100-120 DEG C/h of speed
Progress is heated to 630-680 DEG C, and in this temperature range inside holding 1.5-2 hours;Heated again by 50 DEG C/h of speed
To 870-890 DEG C, and in this temperature range inside holding 4-6 hours;
(2) is cooled down:Stop heating, naturally cool to 400 DEG C, and in this temperature range inside holding 5-7 hours;
(3) is tempered:The intermediate channel ledge that heating arrangement is molded again, firing rate is carried out by 100-120 DEG C/h, and
It is heated to 570-600 DEG C, and in this temperature range inside holding 5-6 hours;
Finally cool down:Stop being cooled to less than 300 DEG C in heating, stove, then naturally cool to room temperature;
3rd, welding step is as follows:
ZG30MnSi and NM400 welds for different alloys steel, and choosing welding wire should be suitable with welding material intensity, and uses two
Carbon dioxide gas mixture protection weldering, can select 55kg grades of high-strength welding wire.
Working environment:Room temperature is not less than 10 DEG C.Weld preheating uses local preheating, heat input 14-17KJ/cm.
Each 30mm in groove both sides is uniformly heated using cutting torch neutral flame wide, preheating temperature is 150-200 DEG C, groove at wearing plate
Preheating temperature is that temperature need to be controlled strictly at 200-250 DEG C, ledge at side, needs to carry out continuous uninterrupted welding in welding process.
Welding current:
Gage of wire |
Backing welding |
Filling weldering |
Cosmetic welding |
Remarks |
The welding wires of φ 1.2 |
230-240A |
280A or so |
No more than 320A |
|
The welding wires of φ 1.6 |
280-300A |
350A or so |
No more than 380A |
|
Arc voltage:I<During 300A, U=26-28V, I>During 300A, U=32-34V
Stem elongation degree (distance of workpiece to ignition tip):
Gage of wire |
I>300A |
I<300A |
Remarks |
The welding wires of φ 1.2 |
12-16mm |
No more than 20 |
|
The welding wires of φ 1.6 |
14-18mm |
No more than 20 |
|
Gas flow:I<During 300A, 15-20L/min is taken;I>During 300A, 15-20L/min is taken
Welding step:
From centre to a backstep welding, then from the other end to middle backstep welding, during welding, must not stitch in welding wire alignment and swing,
And welding wire angle divides equally groove total angle.Previous bar welding bead plays pre- heat effect to latter bar welding bead, and latter bar welding bead is to previous
Bar welding bead plays thermal processes act, can improve the tissue and performance at welding point.There is defect to reprocess in time.To prevent cold crack
The starting the arc can not the starting the arc on mother metal.
Welding sequence:A, the welding of middle plate 2 first weld positive first of weld seam, b, weld sealing run 4 again, and weld seam should be with middle plate
2nd, the rounding off of ledge 1.C, front are using two layers of three roads welding, one of first layer, second layer twice, plate side in first welding, weldering
Seam will be put down, and prevent that ledge side is lack of penetration.Using three layer of four road welding, the 4th road weld cap if weld seam tooled joint is bad.
Intermediate channel ledge 1 is with middle plate 2, the welding process of bottom plate 3, effectively preventing welding deformation amount from being to ensure welding quality
One of key factor.Middle plate uses two-sided double V-groove, and ledge is taken to connect with middle plate to fly to put down at weldering, and reach reliably has with middle plate
Imitate positioning welding.
Because the post welding distortion of intermediate channel shows as slot opening contraction distortion, so slot opening B is defined as B+ in assembling
△ B, add the deformation-compensated amount in opposite direction with welding deformation in advance;Again because in also having ledge after intermediate channel welding relatively
It is lower many less in the deflection distortion of plate, the contraction distortion amount of ledge, so on the deformation-compensated amount △ B of upper and lower slot opening, under △ B
Also it is different, on △ B<Under △ B, that is, when assembling above and below notch size it is trapezoidal, determine deformation-compensated amount on △ B=3mm~
Under 4mm, △ B=4mm~5mm, and lower mouth △ B under than big 2mm~3mm on △ B suitable for reading.
Because each part of middle part bowl assembly has size and uneven deformation, the welding process of different welders is in the presence of poor
Different, these all can make the welding deformation of intermediate channel unstable, so adding rigid fixation again on the basis of prestrain method.
Technological measure is:Notch position is respectively welded with a round steel of φ 40 and draws strong (postwelding removal) above and below intermediate channel two ends, using pressure
Means limit and reduced post welding distortion.
Post weld heat treatment is controlled:Ledge is with after middle plate, bottom plate welding, in order to eliminate welding residual stress, preventing delay from splitting
The generation of the weld defects such as line, reduces welding deformation amount, it is ensured that the product entirety accuracy of manufacture, should be immediately after the completion of intermediate channel welding
Stress relief annealing process is carried out, Stress relieving annealing temperature is 500-550 DEG C, and constant temperature keeps 2-3h.
Above-mentioned embodiment is used for illustrating the present invention, rather than limits the invention, in the spirit of the present invention
In scope of the claims, any modifications and changes made to the present invention both fall within protection scope of the present invention.