CN1187398A

CN1187398A - Technique for integral casting of stainless steel propeller

Info

Publication number: CN1187398A
Application number: CN97108262A
Authority: CN
Inventors: 杨光兴
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-10-16
Filing date: 1997-10-16
Publication date: 1998-07-15
Anticipated expiration: 2017-10-16
Also published as: CN1063687C

Abstract

An integral casting technique for stainless steel propeller technically features that integral casting mould is used, the backing sand is ordinary clay sand, the surfical sand is high bauxite sand, the paint is magnesium sand powder, a composite layer including backing sand, surficial sand and paint is formed during moulding, and open casting system with chosen casting time and temp is used.

Description

Technique for integral casting of stainless steel propeller

The present invention relates to a kind of HACR technique for integral casting of stainless steel propeller.

The general scraper plate that adopts of existing screw propeller casting is made mo(u)ld bottom half in conjunction with pitch plate, meets Ye Duoxiang with the wooden model heart or the sand mo(u)ld heart and makes mo(u)ld top half, because the wooden model heart is made very difficulty, and sand mo(u)ld heart intensity is low, and scale error is big, both cannot say for sure to demonstrate,prove casting quality, and when taking a lot of work again, work efficiency is low.Aspect Modeling Material, general Gao Meng, high-chromium alloy steel casting are made floor sand with quarz sand, make facing sand with magnesia or chromite sand, and these material prices are more expensive, and reuse is relatively poor.Aspect casting system, adopt bottom filling more, every leaf is established a runner gate, and ingate imports along blade plane, and establish chill and lacing wire, core cylinder iron, big rising head, this system's moulding complexity are established in the hub top, the molten steel stroke is long, and temperature is low, easily produces defectives such as misrun, and yield rate only is 60%.New material HACR corrosion-resistant steel (ZL85105573.7) has the few chromium of no nickel, anti-ammonia, alkali, marine corrosion, premium properties such as intensity height, but contain more basic anhydride in its molten steel, scab takes place easily and produce cold shut and surperficial elephant skin, in addition, this steel shrinks big, be easy to generate shrinkage cavity and crackle, thereby the casting difficulty is big.

The object of the present invention is to provide a kind of HACR technique for integral casting of stainless steel propeller.

The present invention be directed to the problem that exists in the casting difficult point of HACR novel stainless steel and the screw propeller foundry technique, worked out and a kind ofly can guarantee casting quality, reduce production costs, can adopt on the whole simultaneously, stove is convenient in the nowel moulding dries, improve the technology of work efficiency, its technological process comprises: make whole mold-sand molding-oven dry-moulding by casting-surface treatment-finished products such as polishing.

The making of whole mold

At first by design calculation secondary processes parameter,, process cover in the iron of propeller hub with the tangent plane plate and the pitch plate of plastic flagstone or the leaf plate of paperboard, each radius; Produce mo(u)ld bottom half with rubbing board, draw line of centers and helix line are completed leaf plate to line, fix each tangent plane plate on leaf plate; Between each tangent plane plate, filling out fast solid filler such as clay, the sodium silicate sand etc. of rapid-curing cutback of energy, repair fairing and become the mould heart, treat to make mo(u)ld top half by leaf after it does admittedly; Unpack to remove the mould heart, cover in the following good iron, mould assembling pour into a mould whole mold blank, this blank is trimmed by the one-time process parameter, and reaches requirement do static balance, whole mold, its material can be steel, aluminium or plastics.

Sand molding

The used floor sand of the present invention is a common clay sand, and facing sand is neutrality or basic matterials such as high-al clay sand, and coating is alkalescence such as magnesia powder material preferably.The facing sand proportioning is: high-al clay sand 100%, and clay 2-10%, sodium silicate 0-15%, moisture content 2-6%, best proportioning is a high-al clay sand 100%, clay 3-5%, sodium silicate 5-8%, moisture content 3-5%.Coating formula is: magnesia powder 100%, and clay 2-8%, sodium silicate or syrup 3-12%, water is an amount of, and best proportioning is a magnesia powder 100%, clay 3-4%, sodium silicate or syrup 5-8%, water is an amount of.During moulding, facing sand and coating are modulated by said ratio, floor sand is put into case and is built reality, at first on the following profile of whole mold, brush the thick facing sand of 10mm and whole mold is put into the common clay sand floor sand, compaction moulding, make it floor sand surface coverage layer of even facing sand, take out whole mold, evenly be coated with again on the facing sand surface and coat, so just make the composite stratotype with common clay sand (floor sand)-high-al clay sand (facing sand)-magnesia powder (coating) composition of propeller mo(u)ld bottom half, according to said method made the composite stratotype of propeller mo(u)ld top half then.

Moulding by casting

The present invention is a unchoked running system, is beneficial to quick cast with big pouring basin.From rising head water inlet, choked flow steadily divides to advance each blade then at the rising head neck, and blade top and leaf locate to set out gas port slightly, consecutive solidification, rising head is with spherical half blind riser, the size of riser neck and highly with the size of watering fluence, adjust, so that the feeding passage is unimpeded.Flow out for the ease of exhaust and slag liquid, offer excessive slag chute with the leaf top slightly at leaf.During cast, the used pouring temperature of the present invention is 1500 ℃-1550 ℃, and be the duration of pouring, and the 300-700Kg molten steel is 8-10 second, and the following molten steel of 300Kg (not comprising 300Kg) is 5 seconds.

Compare with existing propeller foundry engieering, the present invention has following advantage:

1, adopt the whole mold of cover in the iron, mould making process is easier, and is easy to process, and the material-saving that saves time, mold process easily detect and finishing, are convenient to mold itself and reach the balance requirement, thereby can improve casting dimension accuracy;

2, can adopt on the whole, the nowel casting, improved molding process, improve work efficiency more than 5 times;

3, common clay sand (floor sand)-high-al clay sand (facing sand)-magnesia powder (coating) composite stratotype is high temperature resistant, effectively prevents the fusion effect of molten steel to common clay sand, and anti-stick grittiness is good, the Modeling Material cost is low, the old sand reuse is good, and cast(ing) surface is more smooth, and quality is better;

4, the pouring temperature and the time of the present invention's employing are suitable for the HACR corrosion-resistant steel, can effectively prevent the defective of cold shut and elephant skin and the generation of shrinkage cavity and crackle, and yield rate can reach 70-80%.

Embodiment

1, adopts whole aluminum dipping form.

2, Modeling Material.Floor sand-common clay sand; Facing sand proportioning: high-al clay sand 100%, clay 4%, sodium silicate 6%, moisture content 4%; Coating formula: magnesia powder 100%, clay 4%, sodium silicate 7%, water is an amount of.

3, adopt unchoked running system, 1550 ℃ of pouring temperatures, the duration of pouring, the 250Kg molten steel was 5 seconds.

Claims

1, a kind of HACR technique for integral casting of stainless steel propeller, its technological process comprise makes whole mold-sand molding-oven dry-moulding by casting-surface treatment-finished products such as polishing, the invention is characterized in:

1. adopt whole mold;

2. moulding is a common clay sand with the raw MAT'L floor sand, and facing sand is based on high-al clay sand, and coating is based on magnesia powder, and the facing sand proportioning is a high-al clay sand 100%, clay 2-10%, sodium silicate 0-15%, moisture content 2-6%; Coating formula is a magnesia powder 100%, clay 2-8%, and sodium silicate (or syrup) 3-12%, water is an amount of; Form common clay sand (floor sand)-high-al clay sand (facing sand)-magnesia powder (coating) composite stratotype during moulding;

3. adopt unchoked running system, pouring temperature is 1500 ℃-1550 ℃, and be 300Kg-700Kg molten steel 8-10 second the duration of pouring, the following molten steel of 300Kg (not comprising 300Kg) 5 seconds.

2, HACR technique for integral casting of stainless steel propeller according to claim 1, the best proportioning that it is characterized in that facing sand is a high-al clay sand 100%, clay 3-5%, sodium silicate 5-8%, moisture content 3-5%; The best proportioning of coating is a magnesia powder 100%, clay 3-4%, and sodium silicate or syrup 5-8%, water is an amount of.