CN102228956B - Precision fire mould casting process of series sliding bed bedplates for turnouts of high-speed railway lines for passenger transport and special die - Google Patents

Abstract

The invention relates to a precision fire mould casting process of series sliding bed bedplates for turnouts of high-speed railway lines for passenger transport, which comprises the following steps of: 1, designing and making a wax die profiling die; 2, moulding; 3, making a housing; 4, roasting a housing mold; 5, melting and pouring molten steel; 6, removing the housing and cleaning; 7, polishing allowance of a gas cutting gate and finishing weld repairing; 8, thermally heating; 9, blasting and cleaning; and 10, machining. A die structurally and integrally consists of an upper die and a lower die, wherein a step-shaped surface parting loose piece is arranged between the upper die and the lower die, a casting identifier word block loose piece 7 is arranged at the side surface of the lower die and is of a movable insert structure; and the upper die and the lower die are connected and fastened through an upper die positioning pin and a lower die positioning pin which are positioned between the upper die and the lower die and two fastening bolts and butterfly nuts, the fastening bolts and the butterfly nuts are positioned at the diagonal position, and loose piece positioning pins for positioning loose pieces are arranged on positions corresponding to the upper die and the lower die. The precision fire mould casting process is feasible; and the product quality is stable, and the qualification ratio under first acceptance check of products reaches 100 percent.

Description

High-speed passenger special line turnout is slided bed platen precision investment casting technique and particular manufacturing craft with series

Technical field

The invention belongs to the transportation technical field, particularly high-speed passenger special line turnout is slided the manufacturing technology of bed platen with series.

Background technology

Sliding bed platen is the vitals in 250 kilometers of speed per hours, 350 kilometers passenger dedicated railway line track switch products, and sliding bed platen is the plane that the support movable tongue slides, and is again the platform of tongue stationarity when guaranteeing the bullet train operation.Sliding bed platen design material is ZG230-450, its shape is template foundry goods typical slim and that length-width ratio is bigger than normal, whole become the flexural deformation of easily closing up of groove shape, and the end becomes the yielding foundry goods of opening shape, must take multinomial technological measure to ensure physical dimension and the precision of cast product, as the large plane of supporting the tongue slip plane, any casting inner defect must not be arranged simultaneously, need take multinomial technological measure for this reason, guarantee the feasible of each procedure technology of precision investment casting, realized the production of sliding bed platen precision investment casting.

Summary of the invention

Sliding bed platen is the vitals of high-speed passenger special line turnout product, and the casted die mould of properties of product and geometric accuracy requirement is satisfied in design, develops the procedure technology process of a whole set of precision investment casting need of production, guarantees external quality in product.

Line for Passenger Transportation is long strip-board shape with the shape of sliding bed platen steel-casting, the width section is the groove shape, Wall-Thickness Difference is apart from larger, the end is the opening shape, easily distortion, and riser feeding is more difficult, technological design must guarantee that the defectives such as shrinkage porosite, shrinkage cavity must not appear in foundry goods inside, the appearance quality is good, the foundry goods torsional deformation must not occur, must guarantee physical dimension and the precision of foundry goods.Implement in accordance with the following steps in the precision investment casting process for this reason:

(1), the design of wax mould profiling die and making: according to the shape of sliding bed platen, designing mould, and consider setting position, pattern draft, foundry goods sign size and location and the dead head size and location of die joint position, the shrinkage factor of steel-casting, movable pellet; The whole upper and lower mould two parts that adopt of mould structure, it is stepped that die joint becomes, and total shrinkage is controlled at 2.4%;

(2), molding: by product type specification assembling casted die mould, pressure injection enters cerul mould material and pressurize, casted die mould place cooling in entry after, take out wax-pattern and place in entry cooling; Cold wax-pattern after repairing type, then with water excellent assembly welding, the complete wax-pattern group of assembly welding is put into cleaning fluid and clear water, and to clean rear-mounted air-dry;

(3), shell processed: process for making shell adopts the sodium silicate binder full form casting process;

(4), the roasting of shell: dry shell is put into the Baking stove in an orderly manner, determines the roasting standard, takes the low continuous baking modes of high temperature, first 550 ℃ of roastings 60 minutes, then 880 ℃ of roastings 240 minutes, the directly cast of coming out of the stove;

(5), the smelting of molten steel and cast: smelting equipment is 500kg intermediate frequency coreless induction furnace, requirement according to sliding bed platen material ZG250-450, proportioning foundry returns, steel scrap, ferroalloy enter the stove smelting in proportion, and in time adjust the molten steel in the stove chemical composition according to the chemical composition analysis result of sample in stove, until till qualified;

(6), shelling and cleaning: use chipping instrument cleaning cast(ing) surface shell, sand grains and oxide skin, adopt fusion cutting method excision foundry goods pouring and riser systems, and reserve the rising head surplus of 3 millimeters.

(7), polishing gas cutting cast gate surplus and soldering finishing;

(8), heat treatment: adopt normalizing to add tempering process, pack into after sliding bed platen foundry goods dress basket in heat-treatment furnace, and heat-treat according to the heat-treatment of annealing technological specification, each heat Ying Suilu six roots of sensation heat treatment machinery service check test specimen of packing into, the mechanical performance test test specimen should be placed on and the thermocouple same position;

(9), impeller blasting: remove surface scale and residual sand;

(10), machined: the process allowances such as casting amount of dead head, technique stifled muscle, technique lacing wire and interpolation are removed in processing.

The whole employing of mould structure of the present invention is made of upper die and lower die two parts, and the die joint loose piece is stepped between the two, and it is loose plug formula structure that foundry goods sign block loose piece 7 is arranged on the counterdie lateral location; Be connected fasteningly between upper die and lower die by the upper and lower mould alignment pin in the middle of being positioned at and two fastening bolts that are connected diagonal position with wing nut, be provided with the loose piece fastening screw that loose piece is located at the upper die and lower die correspondence position.

Beneficial effect of the present invention: 1, high-speed passenger special line turnout is slided bed platen precision investment casting feasible process with series, constant product quality, and delivery-check qualified rate of product reaches 100%.2, the Product Identifying location specification of the sliding bed of series platen, the font of mark, big or small standard, writing is clear, has promoted the presentation quality of track switch product.3, take many technical measures to ensure physical dimension and the precision of the sliding bed of series platen steel-casting product at aspects such as Design of Dies making, full form casting process, process for machining, greatly reduced the casting inner defect on the large plane of sliding, effective.4, the precision investment casting process improving production operation environment, reduced the environment dust pollution, guaranteed that the employee's is healthy.5, the sliding bed of series platen precision investment casting production technology has improved labor productivity, reduced manufacturing cost, widened production channel and production range, satisfied the needs of track switch product, this process can further be generalized in other iron casting production.6, since producing in February, 2006, produce altogether more than 360 tons of all kinds of sliding bed platen steel-castings, steel-casting is widely used in No. 18 Line for Passenger Transportation track switches of 250 kilometers 60kg/m rail of speed per hour, No. 18 Line for Passenger Transportation track switches of 350 kilometers 60kg/m rail of Shanghai-Nanjing Railway Line speed per hour, No. 42 simple turnouts of the military 350 kilometers 60kg/m rail of line speed per hour of stone, in No. 42 products such as simple turnout of 350 kilometers 60kg/m rail of Shanghai-Nanjing Railway Line speed per hour, product quality is subject to user's favorable comment.

Description of drawings:

Fig. 1 is that track switch slides bed platen die structure dwg (Reference numeral: 1-fastening screw, 2-wing nut, 3-patrix, 4-counterdie, 5-handgrip, 6-upper and lower mould alignment pin, 7-identifier word loose piece, 8-fastening bolt) with series.

The specific embodiment

The present invention is according to following process implementing:

1, the design of wax mould profiling die and making: according to the shape of sliding bed platen, considered during the designing mould structure that die joint position, the shrinkage factor of steel-casting, the setting position of movable pellet, pattern draft, foundry goods identify the technical problems such as size and location and dead head size and location.The whole upper and lower mould two parts that adopt of mould structure, it is stepped that die joint becomes, through engineer testing repeatedly draw that total shrinkage 2.4%(contains that wax-pattern shrinks, the contraction of shell and the contraction of molten steel etc.), it is loose plug formula structure that the foundry goods sign is arranged on lateral location, the dead head size is being considered feeding and collection slag, also be convenient on the basis of this casting forming, be arranged on large plane as double teeming road form, also be convenient to machined and remove.As shown in Figure 1, taked four technical measures during the casted die mould design, 1. respectively designed a technique lacing wire at the two ends, groove position of sliding bed platen, during with solution wax pattern groove position and pouring cast part, the closing in distortion of groove position, guarantee geometric accuracy; 2. set up the technique lacing wire at sliding bed platen open-ended position, open-ended position wax pattern is shunk and pouring cast part opens distortion to solve, and guarantees geometric accuracy; 3. increase the machining allowance of 5～8mm at the back side, inner chamber spring bearing position of sliding bed platen, to solve due to the excessively thin casting that is difficult in bearing position, guarantee geometric accuracy and intensity; 4. the shape of bed platen is slided in combination, the contraction of wax-pattern and steel-casting, and the total shrinkage of Design of Dies is taken as 2.4%.5. large plane " recessed " font two heat energy-saving positions at sliding bed platen arrange 2 oblate waist type rising heads, to strengthen the feeding to foundry goods, eliminate the defectives such as shrinkage porosite, shrinkage cavity of foundry goods inside.

2, molding: by product type specification assembling casted die mould, it is No. 91 (middle temperature mould material) slack waxs (75 ℃ of temperature) that pressure injection enters cerul mould material, injection pressure 0.55MPa, and pressurize 3 minutes, after cooling 45 minutes, take out wax-pattern and place in entry cooling (20 ℃ of water temperatures) in casted die mould placement entry.Cold wax-pattern after repairing type, then and water excellent assembly welding (must not have between weld seam rosin joint gap), the complete wax-pattern group number of assembly welding puts into cleaning fluid and clear water cleans 3 times (removing greasy dirt), rear-mounted is air-dry.

3, shell processed: process for making shell adopts conventional sodium silicate binder full form casting process.1. the configuration of coating: adopt the waterglass bonding to hang the technique that is coated with the ammonium chloride sclerosis, investment precoat: the mixed system of waterglass and 300 order silica flours, flow cup viscosity 13～15 seconds, modulus of water glass M=3.25～3.4, density p=1.26～1.27g/cm2.Reinforced layered slurry: powder mixed system in shop on waterglass and 270 orders, flow cup viscosity 26～30 seconds, modulus of water glass M=3.25～3.4, density p=1.32～1.34g/cm2.2. the dip-coating of shell: hang and to be coated with first and second aspect layer with 40/70 order quartz sand rain type stucco, extension be coated with the 3rd layer to the layer 7 back-up coat with 16/30 order, 10/20 order quartz sand boiling type stucco, time of immersion was for 25 seconds, put into the pond of hardening after every layer of extension is coated with and carry out cure process, the ammonium chloride mass concentration of hardening bath is 28%, need after every layer of sclerosis dry in air 30 minutes natural drying.Before the layer 6 extension is coated with, need emit port part to reinforce iron wire at shell, to increase the cast intensity of shell in addition.3. shell dewaxing: shell is put into and is contained 3～5% ammonium chloride, and the pond temperature is that the dewaxing pool inner water of 98 ℃ boils, the poach time is 50 minutes, after slack wax shells fully, taking out the hot water that shell puts into 90 ℃ of temperature and contain 0.5% hydrochloric acid rinses, rinse after 3 minutes, take out remaining water in the turned letter shell, placed in air natural drying 10 hours.

4, the roasting of shell: dry shell is put into the Baking stove in an orderly manner, determines the roasting standard, takes the low continuous baking modes of high temperature, first 550 ℃ of roastings 60 minutes, then 880 ℃ of roastings 240 minutes, the directly cast of coming out of the stove.

5, the smelting of molten steel and cast: smelting equipment is 500kg intermediate frequency coreless induction furnace, requirement according to sliding bed platen material ZG250-450, proportioning foundry returns, steel scrap, ferroalloy etc. enter the stove smelting in proportion, and in time adjust the molten steel in the stove chemical composition according to the chemical composition analysis result of sample in stove, until till qualified.Before cast, it is firm that the shell that goes out roaster need add sand, with exhaust one by one sand grains foreign material in shell of air intake duct.During cast, the shell temperature must not be lower than 200 ℃, and the molten steel temperature of coming out of the stove is 1600 ℃, take quick method for continuous casting, should be controlled at the duration of pouring in 30 seconds, first with rill cast, increment gradually, when molten steel rises to dead head, slow down poring rate, till molten steel reaches the height of regulation in dead head.For guaranteeing effective feeding of rising head, adopt rice husk slag riser heating and insulating coverture during cast, rising head solidifies the rear surface and is point " U " type shape, to reach effective feeding of foundry goods, reaches the control to quality problems such as sliding bed platen steel-casting shrinkage cavity and porosities

6, shelling and cleaning: use chipping instrument cleaning cast(ing) surface shell, sand grains and oxide skin, adopt fusion cutting method excision foundry goods pouring and riser systems, and reserve the rising head surplus of 3 millimeters.

7, polishing gas cutting cast gate surplus and soldering finishing.

8, heat treatment: adopt normalizing to add tempering process, pack into after sliding bed platen foundry goods dress basket in heat-treatment furnace, and heat-treat according to the heat-treatment of annealing technological specification, each heat Ying Suilu six roots of sensation heat treatment machinery service check test specimen of packing into, the mechanical performance test test specimen should be placed on and the thermocouple same position.

9, impeller blasting: remove surface scale and residual sand.

10, machined: according to the drawing content, determine the process for machining scheme, the process allowances such as casting amount of dead head, technique stifled muscle, technique lacing wire and interpolation are removed in processing.

Particular manufacturing craft of the present invention as shown in Figure 1, the whole employing of mould structure is made of patrix 3 and counterdie 4 two parts, and die joint loose piece 9 is stepped between the two, it is loose plug formula structure that foundry goods sign block loose piece 7 is arranged on counterdie 4 lateral location; Are connected with wing nut by the upper and lower mould alignment pin 6 in the middle of being positioned at and two fastening bolts 8 that are connected diagonal position between patrix 3 and counterdie 4 and connect fasteningly, be provided with at patrix 3 and counterdie 4 correspondence positions the loose piece fastening screw 1 that loose piece 9 is located.

Claims (4)

1. high-speed passenger special line turnout is slided bed platen precision investment casting technique with series, it is characterized in that implementing in accordance with the following steps:

(1), the design of wax mould profiling die and making: according to the shape of sliding bed platen, designing mould, and consider setting position, pattern draft, foundry goods sign size and location and the dead head size and location of die joint position, the shrinkage factor of steel-casting, movable pellet; The whole upper and lower mould two parts that adopt of mould structure, it is stepped that die joint becomes, and total shrinkage is controlled at 2.4%;

(2), molding: by product type specification assembling casted die mould, pressure injection enters cerul mould material and pressurize, casted die mould place cooling in entry after, take out wax-pattern and place in entry cooling; Cold wax-pattern after repairing type, then with water excellent assembly welding, the complete wax-pattern group of assembly welding is put into cleaning fluid and clear water, and to clean rear-mounted air-dry;

(3), shell processed: process for making shell adopts the sodium silicate binder full form casting process;

(4), the roasting of shell: dry shell is put into the Baking stove in an orderly manner, determines the roasting standard, takes the low continuous baking modes of high temperature, first 550 ℃ of roastings 60 minutes, then 880 ℃ of roastings 240 minutes, the directly cast of coming out of the stove;

(5), the smelting of molten steel and cast: smelting equipment is 500kg intermediate frequency coreless induction furnace, requirement according to sliding bed platen material ZG250-450, proportioning foundry returns, steel scrap, ferroalloy enter the stove smelting in proportion, and in time adjust the molten steel in the stove chemical composition according to the chemical composition analysis result of sample in stove, until till qualified;

(6), shelling and cleaning: use chipping instrument cleaning cast(ing) surface shell, sand grains and oxide skin, adopt fusion cutting method excision foundry goods pouring and riser systems, and reserve the rising head surplus of 3 millimeters;

(7), polishing gas cutting cast gate surplus and soldering finishing;

(8), heat treatment: adopt normalizing to add tempering process, pack into after sliding bed platen foundry goods dress basket in heat-treatment furnace, and heat-treat according to the heat-treatment of annealing technological specification, each heat Ying Suilu six roots of sensation heat treatment machinery service check test specimen of packing into, the mechanical performance test test specimen should be placed on and the thermocouple same position;

(9), impeller blasting: remove surface scale and residual sand;

(10), machined: the process allowance of the casting amount of dead head, technique stifled muscle, technique lacing wire and interpolation is removed in processing.

2. described high-speed passenger special line turnout is slided bed platen precision investment casting technique with series according to claim 1, four technical measures have been taked when it is characterized in that the casted die mould design: 1. respectively design a technique lacing wire at the two ends, groove position of sliding bed platen, during with solution wax pattern groove position and pouring cast part, close up and be out of shape in the groove position, guarantees geometric accuracy; 2. set up the technique lacing wire at sliding bed platen open-ended position, open-ended position wax pattern is shunk and pouring cast part opens distortion to solve, and guarantees geometric accuracy; 3. increase the machining allowance of 5～8mm at the back side, inner chamber spring bearing position of sliding bed platen, to solve due to the excessively thin casting that is difficult in bearing position, guarantee geometric accuracy and intensity; 4. the shape of bed platen is slided in combination, the contraction of wax-pattern and steel-casting, and the total shrinkage of Design of Dies is taken as 2.4%; 5. large plane " recessed " font two heat energy-saving positions at sliding bed platen arrange 2 oblate waist type rising heads, to strengthen the feeding to foundry goods, eliminate shrinkage porosite, the shrinkage cavity defect of foundry goods inside.

3. described high-speed passenger special line turnout is slided bed platen precision investment casting technique with series according to claim 1, the sodium silicate binder full form casting process that it is characterized in that the process for making shell employing is implemented in accordance with the following steps: the 1. configuration of coating: adopt the waterglass bonding to hang the technique that is coated with the ammonium chloride sclerosis, investment precoat: the mixed system of waterglass and 300 order silica flours, flow cup viscosity 13～15 seconds, modulus of water glass M=3.25～3.4, density p=1.26～1.27g/cm2; Reinforced layered slurry: powder mixed system in shop on waterglass and 270 orders, flow cup viscosity 26～30 seconds, modulus of water glass M=3.25～3.4, density p=1.32～1.34g/cm2; 2. the dip-coating of shell: hang and to be coated with first and second aspect layer with 40/70 order quartz sand rain type stucco, extension be coated with the 3rd layer to the layer 7 back-up coat with 16/30 order, 10/20 order quartz sand boiling type stucco, time of immersion was for 25 seconds, put into the pond of hardening after every layer of extension is coated with and carry out cure process, the ammonium chloride mass concentration of hardening bath is 28%, need after every layer of sclerosis dry in air 30 minutes natural drying; Before the layer 6 extension is coated with, need emit port part to reinforce iron wire at shell, to increase the cast intensity of shell in addition; 3. shell dewaxing: shell is put into and is contained 3～5% ammonium chloride, and the pond temperature is that the dewaxing pool inner water of 98 ℃ boils, the poach time is 50 minutes, after slack wax shells fully, taking out the hot water that shell puts into 90 ℃ of temperature and contain 0.5% hydrochloric acid rinses, rinse after 3 minutes, take out remaining water in the turned letter shell, placed in air natural drying 10 hours.

4. described high-speed passenger special line turnout is slided bed platen precision investment casting technique with series according to claim 1, the smelting and the cast step that it is characterized in that molten steel also comprise: before cast, it is firm that the shell that goes out roaster need add sand, with exhaust one by one sand grains foreign material in shell of air intake duct; During cast, the shell temperature must not be lower than 200 ℃, the molten steel temperature of coming out of the stove is 1600 ℃, take quick method for continuous casting, should be controlled at the duration of pouring in 30 seconds, first with the rill cast, increment gradually is when molten steel rises to dead head, slow down poring rate, till molten steel reaches the height of regulation in dead head; For guaranteeing effective feeding of rising head, adopt rice husk slag riser heating and insulating coverture during cast, rising head solidifies the rear surface and is point " U " type shape, to reach effective feeding of foundry goods, reaches the control to sliding bed platen steel-casting shrinkage cavity and porosity quality problems.