CN104550723A

CN104550723A - Lost foam casting technology of duplex metal composition hammer head

Info

Publication number: CN104550723A
Application number: CN201310514266.3A
Authority: CN
Inventors: 刘升迁
Original assignee: QINGDAO TIANHENG MACHINERY CO Ltd
Current assignee: QINGDAO TIANHENG MACHINERY CO Ltd
Priority date: 2013-10-28
Filing date: 2013-10-28
Publication date: 2015-04-29

Abstract

The invention discloses a lost foam casting technology of a duplex metal composition hammer head. By lost foam casting method, high-chromium cast iron (liquid) at the head part and carbon steel (a solid) at the handle part are effectively bonded into the duplex metal composition hammer head; the ratio of the liquid metal volume to the solid metal volume for duplex composition casting is 5 to 1, and the bonding form of the two kinds of metal is mechanical bonding; when the volume ratio is 8 to 1, the bonding is firm so as to form good bonding; when the volume ratio is 10 to 1, the bonding form belongs to metallurgical bonding, and the bonding surface is extremely firm; the volume ratio of the two kinds of metal is 8.7 to 1, and he requirement of firm bonding is met. The lost foam casting technology has the beneficial effects that the technological technique is simple, the production cost is low, the yield is high, and the economical and popularization value is obvious.

Description

The lost foam casting process of Double-metal composite hammer

Technical field

The invention belongs to alloy cast iron casting technology field, be specifically related to a kind of lost foam casting process of Double-metal composite hammer.

Background technology

Accept the stone crusher tup produced, original material is potassium steel, and section thickness full-size is 130 mm, and quality is 82 kg, adopts sand casting process.Utilize potassium steel to be hit under load effect and the feature of work hardening occurs to improve wearability, but wearability far can not meet efficient modern production needs.Reason be tup under arms in process institute be hit little, potassium steel hardening effect is not obvious, and wear no resistance building.The shortcoming that frequent shutdown is changed for tup square in service life, operation rate is low, replaces potassium steel tup with rich chromium cast iron one carbon steel composite hammer head.Because lost foam casting has without die joint, without core, without moulding sand binder, operating procedure is simple, the features such as castings production cost is low; So, adopt lost foam casting process to produce Double-metal composite hammer, and have studied the production Technology of Double-metal composite hammer.

Summary of the invention

In order to overcome the problems referred to above that prior art field exists, the object of the invention is to, a kind of lost foam casting process of Double-metal composite hammer is provided.

By the method for lost foam casting, the rich chromium cast iron (liquid) of head and the carbon steel (solid) of shank are combined into Double-metal composite hammer effectively.The liquid metals volume of bimetal composite casting is with solid metal volume than being 5:1, and the combining form of two kinds of metals is mechanical bond; When volume ratio is 8:1, in conjunction with firmly forming good combination; When volume ratio is 10:1, belong to metallurgical binding, faying face is extremely firm.Two kinds of metal volume fractions are 8.7:l, meet and combine firmly requirement.

The lost foam casting process of Double-metal composite hammer provided by the invention, its beneficial effect is: when the solid outstanding volume ratio of liquid state one of Double-metal composite hammer is 8:1, two kinds of corrupt split face binding abilities are strong, and crackle, phenomenon of rupture can not occur.Later stage wearing and tearing cross section is used to demonstrate good bonding state.Adopt the tup of rich chromium cast iron and medium carbon steel composite casting, service life be the 3-4 of potassium steel tup doubly, cost performance has certain advantage.Produce Double-metal composite hammer with lost foam casting process, technology is simple, production cost is low, yield rate is high, there is obvious economic benefit and promotional value.

Detailed description of the invention

Below in conjunction with embodiment, to the lost foam casting process of Double-metal composite hammer provided by the invention, be described in detail.

Embodiment one

Foam plastics mould manufacture craft

The model of head and shank all adopts polystyrene foam plastics to make.Determine that foam plastic density is very important, higher density increases the rigidity of apperance, prevent swabbing, group mould and vanning back-up sand time model deform, and excessive density can increase the defect such as pore, slag inclusion.Be 0.018 ~ 0.020 through overtesting determination foam plastic density.Head and shank model casting shrinkage are 2.0%.With resistance wire cutting machine cutting foamed polystyrene pattern.With foam special glue adhesive model, reduce glue consumption to prevent too much gas and residue as far as possible.Shank model composition position is polished into round-corner transition, in case foundry goods cracks.

Coating and coated technique

The refractory aggregate of coating is the silica flour of 53 my, and binding agent adopts white glue with vinyl, and suspending agent is cellulose, and solvent is water.These materials are added in ball grinding stirring machine by a certain percentage and stirs 4h discharging.Every coating through 55-58 DEG C dry after again brush thick layer be the coating of 1-2 mm.

Mold setting and consolidation

For improving the quality of bimetallic faying face, the shank foundry goods first cast, appearance answers non-scale, iron rust, greasy dirt and sand grains.Faying face mustn't have wedge angle to exist, and prevents stress and occurs crack defect.

By in the preformed hole of shank foundry goods insertion head model cleared up, review tup rotation portion size and should meet 222 mm, knot waters, rising head.Then white glue with vinyl and paper material shutoff gap is used, brushing paint.The tup model assembled is put into bakery to dry.

Wall bleeder sandbox is of a size of 2100 mm x l100 mm x 800mm, and molding sand uses 850 1 425 my quartz sands, and the dry sand that bottom sandbox, lay 200 mm is thick, after vibration ramming, then puts into the tup model assembled, and erects and places.Mold thickness between tup model is that 120 mm. assembles 6 for mono-case.Rising head top mold thickness is greater than 100mm, molding sand vibration l min.On covering sealed plastic film, it is the dry sand of 100 mm that paving is applied thick, in case the iron liquid splashed during cast burns broken plastic sheeting pressure release.

Pouring technology

Head material melting in 1.0 t intermediate frequency furnaces, rich chromium cast iron iron liquid tapping temperature is 1480 ~ 1500 DEG C, and pouring temperature is l400 ~ 1420 DEG C.Adopt 1.0 t rising pouring bag cast, a bag iron liquid casting two sandbox foundry goods.During cast, vacuum cavitations is at 0.04 ~ 0.05 MPa.Starting poring rate should not be too fast, and avoid iron liquid to regurgitate, poring rate should be strengthened in centre, keeps there is a certain amount of iron liquid in cup, when iron liquid rise to emit port part time, then reduce poring rate so that feeding.After cast terminates, maintain 0.03MPa negative pressure 35 min, then close vavuum pump.Foundry goods is outlet after sandbox inside holding 8h.

The removing of dead head

Adopt hammer mode to remove the dead head of foundry goods, the unnecessary amount of rising head root is worn with arm-type abrasive machine, firmly unsuitable excessive during polishing, makes foundry goods flour milling generation micro-crack.

Technology for Heating Processing

The quenching of tup, tempering process.After tup quench cooled, should carry out temper in 4-8h, winter temperature is low should carry out temper within 4h, in case foundry goods generation crack defect.

After testing, tup head (working position) hardness after heat treatment is 58-62HRC.

Claims

1. a lost foam casting process for Double-metal composite hammer, is characterized in that: by the method for lost foam casting, the liquid rich chromium cast iron of head and the solid carbon steel of shank are combined into Double-metal composite hammer effectively; The liquid metals volume of bimetal composite casting is 8.7 with solid metal volume ratio ﹕l; Concrete steps are as follows: (one) foam plastics mould makes, the model of head and shank all adopts polystyrene foam plastics to make, foam plastic density is 0.018 ~ 0.020, and head and shank model casting shrinkage are 2.0%, with resistance wire cutting machine cutting foamed polystyrene pattern; (2) coating and coating, the refractory aggregate of coating is the silica flour of 53 my, binding agent adopts white glue with vinyl, suspending agent is cellulose, solvent is water, these materials are added in ball grinding stirring machine by a certain percentage and stir 4h discharging, every coating through 55-58 DEG C dry after again brush thick layer be the coating of 1-2 mm; (3) mold setting and consolidation, by the preformed hole of shank foundry goods insertion head model cleared up, knot waters, rising head, then uses white glue with vinyl and paper material shutoff gap, brushing paint, the tup model assembled is put into bakery and dries; (4) pouring technology, head material melting in 1.0 t intermediate frequency furnaces, rich chromium cast iron iron liquid tapping temperature is 1480 ~ 1500 DEG C, and pouring temperature is l400 ~ 1420 DEG C, and during cast, vacuum cavitations is at 0.04 ~ 0.05 MPa.