CN104801667B

CN104801667B - Method for preventing generation of casting crack of high temperature alloy mold

Info

Publication number: CN104801667B
Application number: CN201310754362.5A
Authority: CN
Inventors: 李雄; 贺飞; 张旺峰; 景绿路; 张晓冬
Original assignee: Shenyang Aircraft Design and Research Institute Aviation Industry of China AVIC
Current assignee: Shenyang Aircraft Design and Research Institute Aviation Industry of China AVIC
Priority date: 2013-12-31
Filing date: 2013-12-31
Publication date: 2017-05-17
Anticipated expiration: 2033-12-31
Also published as: CN104801667A

Abstract

The invention belongs to the field of high-temperature alloy casting, and relates to improvement of a method for preventing generation of the casting crack of a high temperature alloy mold. The method is characterized by comprising: 1, producing sand mold, wherein mold sand is spread on the bottom portion of a sand box, a wood mold is placed into the sand box, dried clay sand is covered around the wood mold as surface sand, the thickness is 30-80 mm, the mold core surface sand adopts dried clay sand, the center part is hollow or is filled with resin sand, and the thickness is 60-100 mm; 2, drying the mold sand, wherein a molding surface casting coating material is brushed 2-3 times on the mold sand surface so as to cure the sand mold, the mold sand enters a furnace at a temperature of 20-50 DEG C and is heated at a rate of 10-30 DEG C/h along with the furnace, the temperature rises to 320-450 DEG C, the temperature is maintained for 20-40 h, and cooling is performed along with the furnace; and 3, casting, wherein casting is performed in a vacuum induction furnace, the vacuum degree is 10-100 Pa, the casting temperature is 1460-1510 DEG C, and the cooling is performed for not less than 1.5 h in the vacuum chamber after completing the casting. The method of the present invention has the following advantages that: in the case of no addition of the gas forming amount, the casting crack of the large-scale high-temperature alloy mold is effectively solved by improving the casting mold and mold core deformability.

Description

A kind of method for preventing high temperature alloy die casting crackle from producing

Technical field

The invention belongs to the casting field of high temperature alloy, more particularly to one kind prevent high temperature alloy die casting crackle from producing Method improvement.

Background technology

Isothermal forging and hot die forming are often used as forging difficult deformable metal, forge as wrought superalloy, titanium alloy this The less-deformable alloy mould of sample is often heated to 850~1000 DEG C, and mould steel cannot meet such use condition；As mould material The molybdenum-base alloy of material, such as TZM, TZC, still there is very high intensity at 1220 DEG C, but are easy to voloxidation, must be in vacuum or inertia Use under gaseous environment, this considerably increases the complexity and cost of forging.What development was used under atmospheric environment is resistant to height The mold materials of temperature can be greatly lowered forging cost.

The wider casting of K403 (equivalent to the Muscovite К of Ж С 6) and In 100 (equivalent to K417 of China) category purposes Nickel base superalloy, is to make gas-turbine blade and the important source material of other hot parts, due to having under atmospheric environment Good elevated temperature strength and antioxygenic property, in the U.S., Russia and China, Deng states isothermal forging mold materials are often used as.K403 and Fusing/the solidification temperature range of IN100 between 1260~1340 DEG C, because their alloying element species is more, content it is high, to change Mobility during kind casting, general cast temperature is set to 1460~1520 DEG C, because cast temperature and solidification temperature have about 200 The temperature difference, so liquid contraction and solidification shrinkage are more serious, such as feeding is improper, it is easy to cause the casting such as shrinkage cavity, loose to lack Fall into.Model casting compares the type that fills beneficial to molten metal, and investment-casting dimensional accuracy height, surface roughness are low, so being adapted to The so difficult mach material of cast superalloy, but due to the restriction of fusible pattern and investment shell intensity, be unsuitable for casting weigh it is hundreds of Kilogram even several tons of high temperature alloy mould.

Compare with model casting, sand casting have operation it is few, with short production cycle, can be with casting large-scale high temperature alloy module The advantages of.Molding sand used by sand casting is divided into resin sand, water-glass sand, clay-bonded sand etc.；Sand mold good moldability made by resin sand, Size is accurate, collapsibility is good, energy resource consumption is few, but high temperature alloy mould is typically cast in the vacuum room of vaccum sensitive stove Make, the excessive gas forming amount of resin sand will constitute injury to vacuum chamber.Water-glass sand has good fluidity, good permeability and intensity high The advantages of, but pattern draft increased greatly amount of machining, and foundry goods easily sticks sand, and sand mold moisture absorption easily makes foundry goods produce gas hole defect, Not high high-temperature alloy casting is asked also to adopt this molding sand.Clay-bonded sand point green-sand and dry sand, the non-drying of green-sand sand mold, Water content is higher, so foundry goods easily produces the defects such as pore, burning into sand, scab, sand holes, the sand that rises；Dry sand sand mold needs drying, Sand mold intensity is high, good permeability, it is not easy to produce the defects such as sand washing, scab, pore, is suitable to big-and-middle-sized high temperature alloy casting of casting Part.

Usually occurs casting crack during big-and-middle-sized high temperature alloy die casting, casting crack is relevant with casting stress.Casting Stress is divided into thermal stress and shrinkage stress, and thermal stress is that in cooling and process of setting, each position of foundry goods is shunk unbalanced and drawn The stress for rising, if casting section thickness difference is big, material linear shrinkage ratio is big, material plasticity is poor, is easy to become under thermal stress effect Shape and cracking；Shrinkage stress be continue to cool down after casting solidification during, core, casting mold are received during Solid State Contraction, are poured and is emitted Mouthful etc. obstruction and the stress that produces, because shrinkage stress is mainly shown as tension, reach to a certain degree, foundry goods can also produce change Shape and cracking.The linear shrinkage ratio of cast superalloy is more bigger than cast steel, is that the twice of cast iron is more, and its plasticity is very poor, K403, The elongation percentage of IN 100 respectively less than 1/4 and 1/2 (see Fig. 1) of normal steel casting, so, compared with cast steel, cast superalloy It is easier casting crack occur.Using sand casting large-sized high-temperature alloy mould, domestic and foreign literature is not seen in, at home, As forging does bigger and bigger, correspondingly mould is also increasing, and casting crack occurs more and more frequent, brings to production huge Big loss, so, the question of casting crack gesture of cast superalloy mould is resolved required.

The content of the invention

The purpose of the present invention is：For problem present in above-mentioned background technology, propose that one kind prevents high temperature alloy mould The method that casting crack is produced.

The technical scheme is that：A kind of method for preventing high temperature alloy die casting crackle from producing, it is characterised in that Step is as follows：

First, make sand mold：Wooden model is put into after molding sand is completed in the bottom of sandbox, dry type clay is covered around wooden model Used as facing sand, thickness is 30-80mm to sand；Core facing sand adopts dry type clay-bonded sand, and thickness is 60-100mm, center portion using hollow or Insert resin sand；

Second, dry sand mold：In 2~3 times cast moulding coating materials of mould surface brush to solidify sand mold, 20~50 DEG C are entered stove, Heated up with stove with the speed of 10~30 DEG C/h, rise to 320-450 DEG C, be incubated 20~40h, furnace cooling；

3rd, casting：Cast in vaccum sensitive stove, 10~100Pa of vacuum, cast temperature is 1460~1510 DEG C, after casting is finished, the cooling in vacuum room is no less than 1.5h.

It is an advantage of the invention that：It is, in the case where gas forming amount is not increased, have by improving the deformability of casting mold and core Solve to effect the question of casting crack of large-sized high-temperature alloy mould.

Description of the drawings

Fig. 1 is the casting mold schematic diagram of the present invention

1- sandboxes；2- floor sands；3- facing sands；4- die cavities

Fig. 2 is the core schematic diagram of the present invention

Wherein, left figure core center portion is hollow, and right figure core center portion is filled out with the good floor sand of deformability

3- facing sands；2- floor sands；5- is hollow；

Specific embodiment

Below by specific embodiment and combine accompanying drawing the present invention is described in further detail.

A kind of method for preventing high temperature alloy die casting crackle from producing, it is characterised in that step is as follows：

First, make sand mold：Wooden model is put into after molding sand is completed in the bottom of sandbox, dry type clay is covered around wooden model Used as facing sand, thickness is H to sand₁；Core facing sand adopts dry type clay-bonded sand, and thickness is H₂, center portion is using hollow or insert resin sand；

Second, dry sand mold：In 2~3 times cast moulding coating materials of mould surface brush solidifying sand mold, temperature T₁Enter stove, with Stove heats up, and speed is a, rises to temperature T₂, temperature retention time is t₁, cool to room temperature with the furnace；

3rd, casting：Cast in vaccum sensitive stove, vacuum is V, cast temperature T₃, after casting is finished, true Cool time is t2 in empty room.

Embodiment is shown in Table 1.

The instantiation of table 1

Example	H₁, mm	H₂, mm	T₁, DEG C	T₂, DEG C	T₃, DEG C	A, DEG C/h	t₁, h	t₂, h	V, Pa
										Example 1	50	70	20	350	1500	20	25	2	100
Example 2	80	100	50	450	1460	30	40	2.5	70
										Example 3	30	60	25	320	1510	10	20	1.5	10

Claims

1. it is a kind of prevent high temperature alloy die casting crackle produce method, it is characterised in that comprise the steps：

First, make sand mold：Wooden model is put into after molding sand is completed in the bottom of sandbox, dry type clay-bonded sand is covered around wooden model and is made For facing sand, thickness is 30-80mm；Core facing sand adopts dry type clay-bonded sand, and thickness is 60-100mm, and center portion is using hollow or insert Resin sand；

Second, dry sand mold：In 2~3 times cast moulding coating materials of mould surface brush to solidify sand mold, 20~50 DEG C are entered stove, with 10 The speed of~30 DEG C/h heats up with stove, rises to 320-450 DEG C, is incubated 20~40h, furnace cooling；

3rd, casting：Cast in vaccum sensitive stove, 10~100Pa of vacuum, cast temperature at 1460~1510 DEG C, After casting is finished, the cooling in vacuum room is no less than 1.5h.