CN1125264A

CN1125264A - Nodular graphite cast iron spheroidization process for reducing fire loss and saving alloy

Info

Publication number: CN1125264A
Application number: CN 94111535
Authority: CN
Inventors: 王希太
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-12-19
Filing date: 1994-12-19
Publication date: 1996-06-26

Abstract

The present invention provides a spheroidization pocess. It is characterized by that when the melted iron is poured into the ladle, the ladle must be filled up at once so as to raise the absorption of magnesium and magnesium dosage participating in spheroidization, and basically eliminate magnesium light and dust poison. In the course of spheroidization all the melted iron must be rolled and bubbled furiously, so that it can make magnesium and rare earth fully contact with graphitic carbon and other impurities so as to raise the dosage of magnesium participating in spheroidization, make full desulfurization and degasification, remove impurities, purify melted iron, reduce alloy consumption and raise casting quality.

Description

Nodular graphite cast iron spheroidization process for reducing fire loss and saving alloy

The present invention improves to form on the former basis of pouring method, particularly can save the consumption of magnesium-rare earth, and (add-on can drop to 0.9%) reduces the pollution to environment, improves the labor condition of nodularization process, improves casting quality etc., and obvious effects is arranged.Nodular graphite cast iron spheroidization process for reducing fire loss and saving alloy is a kind of spheriodizing technique method, belongs to the spheroidal graphite cast iron technical field.

The existing method spheriodizing technique that pours, most producers all adopt the spheroidizing of dam-type nodularization bag also to have indivedual producers to adopt pit type nodularization bag spheroidizing, no matter adopting the sort of nodularization bag handles, all adopt and get molten iron about 1/2 earlier, after treating that the alloy outburst finishes, get all the other molten iron again, like this because alloy does not have the pressure and the absorption of enough height molten iron when outburst, and cause outburst violent, do not have absorbed magnesium, float to the molten iron surface combustion, produce violent magnesium light, toxic dust, not only waste magnesium-rare earth, worsen environment, produce magnesium oxide again, foundry goods easily produces pore, cinder hole etc.And the dam-type nodularization Bao Qicun that most producers adopt the shortcoming of not noting for people.Dykes and dams the bag end in two, forms two pits, put alloy for one, another plays the effect of molten iron buffered consequently because magnesium is than light many of iron, though outburst is violent in reaction process, it can only upwards react root water and can not react downwards.So nodularization not fully of the molten iron in the pit buffer, be poured into the later stage because the molten iron of not nodularization outflow in the pit buffer, participate among the molten iron of top nodularization, when the molten iron magnesium content is not enough to neutralize not nodularization molten iron, decaying spheroidisation will appear, in order to guarantee not occur decaying spheroidisation, will strengthen factor of assurance, consume magnesium-rare earth more.So the consumption of magnesium-rare earth of producer of producing spheroidal graphite cast iron at present is all about 1.8%, what have surpasses 2%.So not only alloys that consume also produce pore, cinder hole etc., multiple casting flaw owing to magnesium content more.

The purpose of this invention is to provide a kind of ideal spheriodizing technique, reach the consumption that can reduce alloy, can improve the quality of ductile cast iron casting again, improve the work situation of nodularization process, reach and not only reduce cost but also improve the purpose that casting quality is improved working conditions.

The present invention realizes like this, improve the absorption of rare earth magnesium and the magnesium amount that raising participates in nodularization by technique means, it is 1 that concrete mistake is executed, the nodularization bag with the degree of depth in the hole of pit type at 260 millimeters---cover ferrosilicon and iron filings (how much decide of the degree of depth and consumption) above between 360 millimeters and when suitably the tamping molten iron will once be got foot (when worrying outburst molten iron do not vomit bag outer) and gets sufficient alloy and break out owing to molten iron on the size and the molten iron temperature of nodularization bag, there is the molten iron of enough height to absorb, when magnesium is gone here and there to the molten iron surface by the bag end, substantially, be absorbed, moreover because the raising of molten iron height, improved the pressure of molten iron to alloy, and the boiling point of magnesium is corresponding raising along with the raising of pressure, and the raising of magnesium boiling point can reduce explosive power accordingly, so spheroidizing reacion is steadily to carry out under the anti-situation of rolling, because molten iron is once to get foot, all molten iron fill part in the nodularization process and roll and increased the touch opportunity of rare earth magnesium and graphite carbon and other impurity, improve the magnesium amount that participates in nodularization, with fill a part desulfurization degasification removal of contamination, thereby so can reach the low gold consumption that contains, the purpose of high nodulizing grade, and minimizing pore cinder hole, decaying spheroidisation, the quality of raising ductile cast iron casting.

The advantage of technology of the present invention:

1, the magnesium-rare earth in the nodularization process can drop to 0.9% from previous level, has saved the consumption of magnesium-rare earth greatly, reduces cost;

2, method is simple, easy handling;

3, reduced the scaling loss of alloy, fully desulfurization, exhaust, removal of contamination, molten iron nodularization degree is good, and nodulizing grade is higher.

4, reduce pore in the molten iron significantly, casting flaws such as cinder hole reduce casting wasted product, improve the quality of products.

The present invention does not have new requirement to original equipment, raw and auxiliary material, must not increase equipment, must not invest, and adaptability is strong in process of production, and general factory (workshop) all can implement, and effect is remarkable.

Concrete operations scheme of the present invention is as follows:

1, adopt nodularization bag pit type device, the degree of depth of pit is between 260 millimeters to 360 millimeters, and the degree of depth is decided on nodularization bag size and molten iron temperature.

2, cover ferrosilicon and iron filings and suitably tamping on the pit face, how many coverture consumptions is decided on ladle size and molten iron temperature.

3, molten iron is poured hot metal ladle into and will once be got full.

Claims

1, a kind of nodular graphite cast iron spheroidization process for reducing fire loss and saving alloy, adopt pit type nodularization portion, the degree of depth of pit will cover ferrosilicon and iron filings above the pit interalloy between 260 millimeters to 360 millimeters, how many coverings is looked out the temperature of molten iron and is decided, and molten iron is once got full then.

2, according to claim 1, adopt this technology will adjust the degree of depth of hot metal ladle pit, adjusting depth range is 260 millimeters to 360 millimeters.

3, according to claim 1, adopt this technology to want molten iron to pour hot metal ladle into and once get full.

4, according to claim 1, to cover a certain amount of ferrosilicon and iron filings above the pit interalloy, and suitably tamping.