CN102294467A

CN102294467A - Method for producing large-sized cast

Info

Publication number: CN102294467A
Application number: CN2011102217989A
Authority: CN
Inventors: 岑启宏; 王治国; 刘晓林; 刘静; 孙吉明
Original assignee: XUZHOU SHENGHAI MACHINERY MANUFACTURING TECHNOLOGY Co Ltd
Current assignee: XUZHOU SHENGHAI MACHINERY MANUFACTURING TECHNOLOGY Co Ltd
Priority date: 2011-07-28
Filing date: 2011-07-28
Publication date: 2011-12-28

Abstract

The invention discloses a method for producing a large-sized cast, which belongs to the field of casting. The method for producing the large-sized cast is mainly suitable for a large-sized gray cast iron component with low requirement on the mechanical properties of a counterweight and the like. A low-carbon steel bar of which the surface is clean and has no oil stain or iron rust, a pig iron ingot of which the surface has no oil stain or included slag and returns are placed inside a casting mould; then, molten iron after being smelted is poured into the casting mould in which the steel bar, the pig iron ingot and the returns are placed; the steel bar, the pig iron ingot and the returns are molten under the action of the high-temperature molten iron; and meanwhile, the cast is solidified under chilling to form metallurgical bonding so as to finally obtain the qualified cast. The method for producing the large-sized cast has the advantages that the qualification rate of the process of the cast can be fully enhanced, the consumption of energy resources is lowered, the solidifying time of the large-sized cast is shortened, and the production efficiency is effectively enhanced.

Description

A kind of heavy castings production method

Affiliated technical field

The present invention relates to a kind of heavy castings production method, belong to casting and mechanical manufacturing field.Mainly be applicable to the less demanding large-scale grey iron spares of mechanical performance such as counterweight, its mechanical performance satisfies the requirement of HT150.

Background technology

Common foundry technology process need will pour into casting mold after the fusing of metal charges such as pig iron, foundry returns, steel scrap.A large amount of iron liquid that large-scale counterweight foundry goods need use, its fusion process need consume a large amount of energy.If can reduce the consumption of iron liquid in the heavy castings production process, for energy-saving and cost-reducing significant.

Counterweight is the heavy castings of large-scale engineering machinery indispensabilities such as bull-dozer, crane.It is less demanding to mechanical performance, mainly need satisfy the requirement of apparent size and tolerance and surface smoothness etc.But its casting section thickness often surpasses 300mm, and foundry goods weighs several tons and even tens of tons, and setting time reaches a few hours and even tens of hours, causes the production cycle long, and efficient is low.Therefore shorten setting time, for improving castings production efficient, significant.

For shortening setting time, common technological measure is to add circulating water cooling system by external chill or in core for cast to realize.These method complex technical process, poor reliability as the pressure cooling system of a kind of thick and large section casting parts of disclosed application number 200710144925.3, are controlled the solidified structure of large-scale ductile iron spare by strengthening the cooling setting-time control.In existing disclosed document, do not relate to and reduce the method that iron liquid consumption obtains qualified foundry goods.

Summary of the invention

The invention provides a kind of heavy castings production method, utilize pig iron, foundry returns, steel scrap etc., reduce iron liquid consumption, shorten setting time as internal densener.

The present invention realizes with following technical scheme: a kind of heavy castings production method, the pig iron and the foundry returns that the no greasy dirt of the low carbon steel strip of cleaning surfaces, no greasy dirt, no iron rust and surface are not had slag inclusion place casting mold inside, and its total consumption is 30%～50% of a foundry goods gross weight; Then the iron liquid after the melting is poured in the casting mold that is placed with steel bar and pig iron, foundry returns; Steel bar, pig iron, foundry returns melt under the effect of high temperature iron liquid, and foundry goods is solidified under Quench, form metallurgical binding, finally obtain qualified foundry goods.

Described low carbon steel strip places the foundry goods outer wall, and foundry returns, pig iron etc. places foundry goods die cavity inside,

Described iron liquid cast temperature is 1250 degrees centigrade～1350 degrees centigrade.

Its processing step is:

1) with low carbon steel strip, foundry returns, pig iron pickling oven dry, removes surface and oil contaminant iron rust and field trash;

2) after moulding finishes, low carbon steel strip is placed the foundry goods outer wall, foundry returns, pig iron etc. places foundry goods die cavity inside, and total consumption of mild steel, foundry returns, pig iron etc. is about 30%～50% of foundry goods gross weight;

3) the iron liquid after the melting pours in the casting mold that is placed with low carbon steel strip and pig iron, foundry returns, 1250 degrees centigrade～1350 degrees centigrade of cast temperatures;

The invention has the beneficial effects as follows: can fully improve casting process yield, reduce energy resource consumption, shorten the setting time of heavy castings, effectively enhance productivity.The production that is applied to heavy castings simple in structure such as engineering machinery counter weight has significant advantage.

The specific embodiment

Embodiment 1

Use the present invention to produce 15 tons of excavator counterweight foundry goods.With low carbon steel strip, foundry returns, pig iron pickling oven dry, remove surface and oil contaminant iron rust and field trash earlier.After moulding finishes, lay low carbon steel strip at the casting mold lower surface, place foundry returns, pig iron etc. then and amount to 6 tons.Mould assembling then.After the fusing of iron liquid finishes, iron liquid is poured into casting mold.Steel bar, pig iron, foundry returns melt under the effect of high temperature iron liquid, and foundry goods is solidified under Quench.Behind the foundry goods cool to room temperature, the analysis showed that through body sampling that the inner no shrinkage cavity shrinkage porosity of foundry goods is mingled with defectives such as cold shut, tensile strength 138MPa reaches the specification requirement of HT150, satisfies the technical conditions of foundry goods as counterweight.Use this technology, it is over half to shorten the castings production cycle, and energy savings consumes more than 40%.

Claims

1. a heavy castings production method is characterized in that, the pig iron and the foundry returns that the no greasy dirt of the low carbon steel strip of cleaning surfaces, no greasy dirt, no iron rust and surface are not had slag inclusion place casting mold inside, and its total consumption is 30%～50% of a foundry goods gross weight; Then the iron liquid after the melting is poured in the casting mold that is placed with steel bar and pig iron, foundry returns; Steel bar, pig iron, foundry returns melt under the effect of high temperature iron liquid, and foundry goods is solidified under Quench, form metallurgical binding, finally obtain qualified foundry goods.

2. a kind of heavy castings production method according to claim 1 is characterized in that described low carbon steel strip places the foundry goods outer wall, and foundry returns, pig iron etc. places foundry goods die cavity inside.

3. a kind of heavy castings production method according to claim 1 is characterized in that, described iron liquid cast temperature is 1250 degrees centigrade～1350 degrees centigrade.