SU897389A1 - Ingot mould for casting steel - Google Patents

Description

I

The invention relates to metallurgy, namely to casting molds for steel. :

Known detachable molds, containing the outer casing and the inner shell, placed relative to each other with a gap of 1.

Closest to the offer is a mold consisting of an inner insert of steel housed in an outer casing of cast iron 2.

Due to the significant difference in temperature and the cross section of the mold, the increased temperature difference increases due to the limited thickness of the steel layer, the presence of the surface section and the associated thermal expansion and differences in linear expansion coefficients during the operation of the two aloe molds. to reduce stresses are not provided, these stresses lead to warping of the steel insert or to cracks in the housing, which reduces the serviceability of the molds.

The purpose of the invention is to increase the service life of the molds.

The goal is achieved by the fact that in a mold containing a multifaceted inner insert made of steel and an outer case of cast iron, on the inner surface of the outer case in the areas of the edges adjacent to the corners, along all their height, there are notches, compensation gaps, whose width is 0, 0.009 width the insertion faces, and their length in cross section from the angle to the face center is 3.0-4.5 wall thickness of the inner insert, and the ratio of wall thicknesses of the said insert and body is 0.5-0.9.

Pa drawing shows the mold, cut. .

The mold consists of body 1, insert 2, in the corners between which

20, compensation gaps 3 are made, while A is the width of the insert face, B is the wall thickness of the insert, C is the width of the compensation gap, D is the length of the compensation gap, E is the wall thickness of the body.

The mold is obtained by pouring the cast iron. in a mold with a pre-installed insert 2. The formation of the cavity of the compensation gap 3 can be carried out, in particular, by installing covers made of steel sheet.

B. For the prepared mold, the ratio of the wall thickness of the insert 2 and the body 1 of cast iron in the range of 0.5-0.9 is observed. The width of the compensation gap 3 is 0.0050, 012 widths perpendicular to the gap 3 of the wall of the insert 2. The length of the compensation gap 3 is 3.0-4.5 of the thickness perpendicular to the gap of the wall of the insert 2.

During operation of the mold, after the steel has been poured into it, solidification and cooling, ingot and warming of the mold occur. The ratio of the thickness of the insert 2 and the housing 1 is 0.5-0.9 and limits the temperature difference between the insert 2 and the housing 1.

The expansion of the steel insert 2 is compensated by the gap 3, and the above ratios are necessary for the effective operation of the mold.

The ratio of the wall thickness of the insert 2 made of steel and the body 1 of cast iron is less than 0.5, and the width of the compensation gaps 3 is less than 0.003 width perpendicular to the wall of the insert 2, this will lead to an increase in thermal stresses, cracks in the case 1 and warping of the insert 2 .

If the ratio of the wall thickness of the insert 2 made of steel and the body 1 of cast iron is greater than 0.9, and the width of the compensation gaps 3 is greater than 0.009 the width of the wall perpendicular to the gap, this may lead to the possibility of warping the insert 2 within the remaining part of the insert 2 3

When the relative length of the gap 3 is less than 3.0 thickness perpendicular to the gap of the wall of the insert 2, the expansion of the wall of the insert 2 is transmitted to the perpendicular wall of the housing 1, causing cracks.

Increasing the relative distance of the gap 3 to over 4.5 the thickness perpendicular to the gap of the wall of the insert 2 is not rational, since the limitation of the warping of the insert 2 is reduced by the body 1, and the overall heat exchange between the insert 2 and the body 1 is reduced, and finally the solidification time ingot, lengthening the working cycle of the mold, which is undesirable.

If these ratios are observed, minimum thermal stresses are provided that do not exceed the proportionality limit of steel in the insert and the strength of cast iron in the housing, prevention of distortion of the insert and the absence of

 cracks in the body, high operational resistance of molds is achieved.

The durability of the proposed molds is 2-4 times greater than that of lime molds.

0 The economic effect according to

to the calculation, the volume of production of molds 30 thousand tons will be 648 thousand rubles. in year.

Claims (1)

1. German patent W 253939, 22 D 7 / oa. 1910. class Ъ: 2. The patent of France W 1201568, kl. In 22 D, 1960.