The casting die of exhaust valve of marine diesel engine valve casing foundry goods and the casting technique of described valve casing
Technical field
The present invention relates to casting technique, be specifically related to a kind of casting die of exhaust valve of marine diesel engine valve casing foundry goods and the casting technique of described valve casing.
Background technology
Described exhaust valve of marine diesel engine valve casing is that its volume is φ 152 * high 352mm, the steel-casting of the 32Kg that weighs.It is the strength member of described diesel exhaust valve.On industrial production, described valve casing rough casting generally adopts the cast molding of low-carbon (LC) chromium alloyed steel.The chemical analysis of described material is: C0.12 ~ 0.17, Si0.30 ~ 0.40, Mn0.40 ~ 0.60, Cr2.80 ~ 3.20, Mo0.35 ~ 0.65, Cu≤0.40, Ni≤0.40, S≤0.04, P≤0.04, Fe surplus; The requirement of the described mechanical property of materials is: tensile strength 〉=620Mpa, yield strength 〉=420Mpa, percentage elongation 〉=13%, ballistic work AKV
2〉=25J, hardness 179 ~ 225HB.Require described valve casing not produce in the 20Mpa pressure test and press the leakage situation.
Planform more complicated due to described valve casing, wall thickness variation is larger, so that foundry goods cooling degree of each several part in casting process is inhomogeneous, and extremely easily partly produces Shinkage and dispersed porosity at wall thickness, extremely easily produces again molten steel in thin-walled portion and fills that type is bad and contracting is flat.Thereby the percentage of A-class goods of described valve casing foundry goods is lower, has the casting flaws such as surperficial scab; The manufactured goods valve casing usually can be pressed leakage problem.For this reason, present described valve casing foundry goods is still needed by external import.
Summary of the invention
The present invention aims to provide a kind of rational in infrastructure, cooling evenly at foundry goods casting cycle medium casting each several part, be difficult for producing the defectives such as shrinkage porosite, shrinkage cavity and surperficial scab, the casting die of the exhaust valve of marine diesel engine valve casing foundry goods that the foundry goods percentage of A-class goods is higher and the casting technique of described valve casing, to overcome the casting flaw of described valve casing, fundamentally improve the quality of described valve casing, for described valve casing foundry goods production domesticization provides support.
The present invention realizes that the technical scheme that its purpose is taked is:
A kind of casting die of exhaust valve of marine diesel engine valve casing foundry goods, described casting die are resin sand mould, and its:
Take the longitudinal center line of the wicket of described foundry goods and large window as die joint, consist of respectively upper and lower involutory upper impression resin sand mould and lower impressions resin sand mould with phenolic sand molding;
Position, outer face at the described casting flange die cavity of described upper impression resin sand mould and lower impressions resin sand mould is furnished with contoured chill;
Drop on the core in the resin sand mould die cavity, comprise by resin sand through molded the first core got of core, the second core, the 3rd core and the 4th core; Between the first core and the second core, be connected and fixed by the earthenware that meets described cast casting technological requirement; The other end of the first core is fixed with contoured chill phase setting-in, and an end setting-in of the other end of the second core and the 3rd core is fixed, and the other end of the 3rd core is fixed with upper impression resin sand mould and lower impressions resin sand mould phase setting-in; The 4th core is fixed on the upper impression resin sand mould;
Be positioned at the surface at the cone table position of the second core, be laid with the chrome ore layer of sand;
The runner system that comprises sprue, cross gate and ingate is laid on the die joint of upper impression resin sand mould and lower impressions resin sand mould; And the intersection of cross gate and ingate is provided with collection slag feeding blind riser;
Being used for the rising head of feeding is respectively the first rising head and the second rising head; The first rising head is arranged in upper impression resin sand mould directly over the first core middle part, and the second rising head is arranged in the upper impression resin sand mould that gets close to directly over described foundry goods wicket core.
can be understood by above given technical scheme, casting die of the present invention, owing to having arranged contoured chill and chrome ore sand bed at the die cavity of described casting section thickness part, and make the casting section thickness part evenly cooling with the thin part of wall, partly arranged feeding head at described casting section thickness, avoided the shrinkage porosite shrinkage cavity defect, and adopt the runner system of collection slag feeding, avoided the dreg defect of foundry goods inside, under the casting technique condition that the present invention advocates, the percentage of A-class goods of described valve casing foundry goods is improved, avoided pressing the generation of leakage problem, thereby realized purpose of the present invention.
In technique scheme, the present invention also advocates, the thickness of described contoured chill is 20 ~ 40mm, the height of described collection slag feeding blind riser is 145 ~ 155mm, described the first rising head and the second rising head are the oval open riser of φ 80 * 120mm or heat preservation blind riser, and the thickness of described chrome ore layer of sand is 15 ~ 20mm; Also comprise being located in upper impression resin-sand mould and being positioned at the steam vent that described casting flange die cavity pushes up, the diameter of steam vent is φ 8 ~ 15mm.This technical scheme is to guarantee casting quality, avoids the effective measures of described casting flaw, but is not limited to this.Described thickness, height and diameter etc. all can be done concrete adjustment according to actual needs.But the present invention does not advocate, described thickness, height and diameter are less than the scope of described size.
In order to improve the production efficiency of foundry goods of the present invention, improve the yield rate of foundry goods, the present invention also advocates, described casting die is one case two mould, at least separately be arranged symmetrically with at a distance of 340 mm between 2 resin sand die cavity longitudinal center lines, and 2 each own ingates of resin sand mould die cavity, and sprue and the cross gate of shared 1 runner system.Certainly, be not limited to this.If the license of produced on-site condition can be also one case multimode.Under the condition of one case multimode, described runner system should be done necessary adjustment.
The casting technique of the described valve casing that the present invention advocates is:
A kind of casting technique of valve casing as previously discussed comprises batching, melting, and casting die matched moulds pre-treatment and join the core matched moulds, cast and cleaning, and its:
Take above-mentioned casting die as the pouring molten steel shaping mould;
Described batching is with mild steel waste material and stainless steel waste material and molybdenum-iron, by the chemical composition of described valve casing, carries out respectively weighing and burden;
Described melting is to adopt intermediate frequency furnace remelting furnace charge, before molten steel is come out of the stove, adds aluminium deoxidation by 1 ‰ of Metal Weight, adds molten steel scavenger by Metal Weight 3 ‰ when molten steel is come out of the stove in ladle, and tapping temperature is controlled in 1590 ~ 1610 ℃ of scopes;
Described casting die matched moulds pre-treatment and join the core matched moulds is first at external mold and whose surfaces brushing high-temperature resistant coating respectively, and joins the core matched moulds after the igniting drying again, and pours into a mould in 4 h;
Described cast is that the pouring molten steel temperature is controlled in 1550 ~ 1600 ℃ of scopes; Interval 3 ~ 5s after cast finishes, spot pouring mouth and/or some open riser 1 ~ 2 time;
Described cleaning is the unpacking knockout of 6h after cast, cuts off dead head after Shot Blasting, namely gets described valve casing foundry goods.
In technique scheme, the present invention advocates, described molten steel scavenger is Si-Ca-Ba clad steel water scavengine agent, or silico-calcium clad steel water scavengine agent, or lanthanide rare molten steel water purification agent.The present invention is Si-Ca-Ba clad steel water scavengine agent preferably.
In technique scheme, the present invention advocates, described high-temperature resistant coating is zirconium English powder high-temperature resistant coating, or the schmigel high-temperature resistant coating.The present invention is zirconium English powder high-temperature resistant coating preferably.
After technique scheme is implemented, casting die of the present invention is rational in infrastructure, layout is advanced, the easy easy control of casting technique of the present invention, adopt the described valve casing casting quality of the present invention's casting good, can not produce the casting flaws such as shrinkage porosite, shrinkage cavity and surperficial scab, having avoided described valve casing finished product to press the characteristics such as generation of leakage problem, is apparent.
Description of drawings
Fig. 1 is that the master of valve casing foundry goods of the present invention looks schematic diagram, and ao shown in figure is pit,
Fig. 2 is the A-A cutaway view of Fig. 1;
Fig. 3 is the top view of Fig. 1;
Fig. 4 is the structural representation of casting die of the present invention;
Fig. 5 is that the B-B of Fig. 4 is to schematic diagram;
Fig. 6 is the schematic flow sheet of casting technique of the present invention.
The specific embodiment
Below contrast accompanying drawing, embodiments of the present invention are described specifically.
One of specific embodiment also please be joined as shown in accompanying drawing 2,4 and be read accompanying drawing 5.
A kind of casting die of middle low speed exhaust valve of marine diesel engine valve casing foundry goods, described casting die is resin sand mould, and its:
Take the longitudinal center line of the wicket 1 of described foundry goods and large window 2 as die joint, consist of respectively upper and lower involutory upper impression resin sand mould 3 and lower impressions resin sand mould 4 with phenolic sand molding;
Position, outer face at the described casting flange die cavity 5 of described upper impression resin sand mould 3 and lower impressions resin sand mould 4 is furnished with contoured chill 6;
Drop on the core in the resin sand mould die cavity, comprise by resin sand through molded the first core 7 got of core, the second core 8, the 3rd core 9 and the 4th core 14; Between the first core 7 and the second core 8, be connected and fixed by the earthenware 10 that meets described cast casting technological requirement; The other end of the first core 7 is fixed with contoured chill 6 phase setting-ins, and an end setting-in of the other end of the second core 8 and the 3rd core 9 is fixed, and the other end of the 3rd core is fixed with upper impression resin sand mould 3 and lower impressions resin sand mould 4 phase setting-ins; The 4th core 14 is fixed on upper impression resin sand mould 3;
Be positioned at the surface at the cone table 8-1 position of the second core 8, be laid with chrome ore layer of sand 15;
The runner system that comprises sprue 11-1, cross gate 11-2 and ingate 11-3 is laid on the die joint of upper impression resin sand mould 3 and lower impressions resin sand mould 4; And the intersection of cross gate 11-2 and ingate 11-3 is provided with collection slag feeding blind riser 11-4;
Being used for the rising head of feeding is respectively the first rising head 12 and the second rising head 13; The first rising head 12 is arranged in upper impression resin sand mould 3 directly over the first core 7 middle parts, and the second rising head 13 is arranged in the upper impression resin sand mould 3 that gets close to directly over described foundry goods wicket 1 core.Namely be arranged in the wall thickness position of valve casing of the present invention.
The thickness of described contoured chill is 20 ~ 40mm, the height of described collection slag feeding blind riser 11-4 is 145 ~ 155mm, described the first rising head 12 and the second rising head 13 are the oval open riser of φ 80 * 120mm or heat preservation blind riser, and the thickness of described chrome ore layer of sand 15 is 15 ~ 20mm; Also comprise being located in upper impression resin sand mould 3 and being positioned at the steam vent 16 that described casting flange die cavity 5 pushes up, the diameter of steam vent 16 is φ 8 ~ 15mm.
One of specific embodiment, described is the casting die of the described valve casing foundry goods of one case one mould.
Two of the specific embodiment is as shown in accompanying drawing 2,4,5.
A kind of casting die of middle low speed exhaust valve of marine diesel engine valve casing foundry goods, described casting die is resin sand mould, and its:
Take the longitudinal center line of the wicket 1 of described foundry goods and large window 2 as die joint, consist of respectively upper and lower involutory upper impression resin sand mould 3 and lower impressions resin sand mould 4 with phenolic sand molding;
Lateral surface position at the described casting flange die cavity 5 of described upper impression resin sand mould 3 and lower impressions resin sand mould 4 is furnished with contoured chill 6;
Drop on the core in the resin sand mould die cavity, comprise by resin sand through molded the first core 7 got of core, the second core 8, the 3rd core 9 and the 4th core 14; Between the first core 7 and the second core 8, be connected and fixed by the earthenware 10 that meets described cast casting technological requirement; The other end of the first core 7 is fixed with contoured chill 6 phase setting-ins, and an end setting-in of the other end of the second core 8 and the 3rd core 9 is fixed, and the other end of the 3rd core is fixed with upper impression resin sand mould 3 and lower impressions resin sand mould 4 phase setting-ins; The 4th core 14 is fixed on upper impression resin sand mould 3;
Be positioned at the surface at the cone table 8-1 position of the second core 8, be laid with chrome ore layer of sand 15;
The runner system that comprises sprue 11-1, cross gate 11-2 and ingate 11-3 is laid on the die joint of upper impression resin sand mould 3 and lower impressions resin sand mould 4; And the intersection of cross gate 11-2 and ingate 11-3 is provided with collection slag feeding blind riser 11-4;
Being used for the rising head of feeding is respectively the first rising head 12 and the second rising head 13; The first rising head 12 is arranged in upper impression resin sand mould 3 directly over the first core 7 middle parts, and the second rising head 13 is arranged in the upper impression resin sand mould 3 that gets close to directly over described foundry goods wicket 1 core.
The thickness of described contoured chill is 20 ~ 40mm, the height of described collection slag feeding blind riser 11-4 is 145 ~ 155mm, described the first rising head 12 and the second rising head 13 are the oval open riser of φ 80 * 120mm or heat preservation blind riser, and the thickness of described chrome ore layer of sand 15 is 15 ~ 20mm; Also comprise being located in upper impression resin sand mould 3 and being positioned at the steam vent 16 that described casting flange die cavity 5 pushes up, the diameter of steam vent 16 is φ 8 ~ 15mm.
Described casting die is one case two mould, separately is arranged symmetrically with at a distance of 340 mm at least between 2 resin sand die cavity longitudinal center lines, and 2 each own ingate 11-3 of resin sand mould die cavity, and sprue 11-1 and the cross gate 11-2 of shared 1 runner system.
Two of the specific embodiment, described is the casting die of the described valve casing foundry goods of one case two mould.Because 2 casting dies share a runner system, can reduce the materials of runner system, and improve the yield rate of foundry goods.
Three of the specific embodiment, as shown in Figure 6.
A kind of as described in the casting technique of low speed exhaust valve of marine diesel engine valve casing, comprise batching, melting, casting die matched moulds pre-treatment and join the core matched moulds, cast and clearing up, and its:
Take one of specific embodiment or two described casting dies as the pouring molten steel shaping mould;
Described batching is with mild steel waste material and stainless steel waste material and molybdenum-iron, by the chemical composition of described valve casing, carries out respectively weighing and burden;
Described melting is to adopt intermediate frequency furnace remelting furnace charge, before molten steel is come out of the stove, adds the aluminium block deoxidation by 1 ‰ of Metal Weight, adds molten steel scavenger by Metal Weight 3 ‰ when molten steel is come out of the stove in ladle, and tapping temperature is controlled in 1590 ~ 1610 ℃ of scopes;
Described casting die matched moulds pre-treatment and join the core matched moulds is first at external mold and whose surfaces brushing high-temperature resistant coating respectively, and joins the core matched moulds after the igniting drying again, and pours into a mould in 4 h;
Described cast is that the pouring molten steel temperature is controlled in 1550 ~ 1600 ℃ of scopes; Interval 3 ~ 5s after cast finishes, spot pouring mouth and/or some open riser 1 ~ 2 time;
Described cleaning is the unpacking knockout of 6h after cast, cuts off dead head after Shot Blasting, namely gets the valve casing foundry goods.
And described molten steel scavenger is Si-Ca-Ba clad steel water scavengine agent; Described high-temperature resistant coating is zirconium English powder high-temperature resistant coating.
And the igniting that should be noted that the pre-treatment of described casting die matched moulds is dry, is after the brushing high-temperature resistant coating, with the high-temperature resistant coating of brushing on the casting die surface that ignite such as lighter, make it lose moisture content and drying, and pour into a mould in 4h, to avoid also tide of high-temperature resistant coating moisture absorption.Described spot pouring mouth and/or some open riser are jargons in the industry, and hole irrigation is teeming.
Lab scale of the present invention and pilot scale effect are good.For domestic described valve casing provides support.