SU1532196A1 - Split shaped ring to casting mould for casting sized rolling mill rolls - Google Patents

Abstract

The invention relates to foundry, specifically to the casting of rolled calibrated rolls. The purpose of the invention is to obtain high-quality calibrated rolls. Preventing the formation of hot cracks on the rolls at the joints of the parts of the knee forming rings is due to the fact that the joint planes of the latter are designed in such a way that the butt lines of any ring surface form an angle of 40-50 ° with the plane of axial symmetry of the ring. 4 il.

Description

one

(21) 4439598 / 23-02

(22) 04/25/88

(46) 12/30/89. Bul Number 48

(71) Magnitogorsk Institute of Mining and Metallurgy. G.I.Nosova

and Kushvinsky mill rolls

(72) F. D. Kashchenko, L. A. Fetn Epa, R. Kh. Gimaletdinov and A. V. Palamarchuk (53) 621.74.043 (088.8)

(56) USSR author's certificate No. 550233, cl. B 22 D 13/00, 1976.

USSR author's certificate 104030, cl. B 22 D 15/00, 1957.

(54) CONNECTING GRADDING RING TO CASTING FORM FOR CASTING CALIBRATED ROLLING ROLLS (57) The invention relates to foundry, specifically to the casting of rolled grooved rolls. The purpose of the invention is to obtain high-quality calibrated rolls. Preventing the formation of hot cracks on the rolls at the joints of the grading rings of the rings is due to the fact that the joint planes of the latter are designed so that the cTiiiKa lines of any ring surface form an angle of 40-50 ° .4 silt .

The invention relates to foundry, specifically to the casting of rolled calibrated rolls.

The purpose of the invention is to obtain high-quality calibrated rolls.

FIG. 1-2, a ring is shown for forming a roll roll for rolling a circle or pipe; FIG. 3-4 is a ring for the formation of a slush-type strap.

The profiling ring consists of two or more parts. Each cut or joint of the ring is made as follows. At the profiling ring (Fig. 1) to form a roll roll for rolling the pipe (angle, circle), the plane of the optimal cut passes through the center of the symmetry of the ring at an angle of about 43 ° to the axis of symmetry OX. In the case of the profile ring, in order to form an internal caliber, the incision plane passes at an angle ø6, 50 to the tangent to the outer point A (B) of the beginning of the cut (Fig. 2) at an angle of ° C to 3 ° to the plane of axial symmetry of the ring.

Thus, the line of the AE junction forms an angle of 90 ° –6 ° 40 ° with the plane of transverse symmetry of the ring passing through point A, and the line of the AU 90 interface.

For ease of installation and centering and partly of girder rings in a coca keel, it is advisable to make each section of the ring in two mutually perpendicular planes with their line of intersection of the DM (Fig. 1) lying

in the plane of the longitudinal SIM -1РТРИН

rings.

The ring works as follows.

c s

g

In the area of the junction between the parts of the rings, where there is a gas gap 0.5-2.0 mm wide, the thickness is frozen. the crusts are somewhat smaller than on the remaining surface of the rings. But since the zone with a weakened section is at an angle to the plane of probable formation of longitudinal hot cracks, where only tensile stresses act, the magnitude of the latter decreases by I / COS 0 times, i.e. in our case, on average, 1.4 times (at 40-50). Such a reduction in the load on the solidifying metal crust prevents it from breaking, i.e. from the appearance of hot longitudinal cracks in the roll caliber.

As the angle decreases to about 40, the tensile stresses increase, which is undesirable. Angle increase

tL 50 ° is limited by the inconvenience of cutting the ring, as well as the danger of transverse hot cracks, i.e. the angle limits of 40-50 ° are most acceptable

Examples of the use of profiling rings.

The most high-quality profiled roll is obtained when it is manufactured by a centrifugal casting method using withdrawable aluminum forming rings. B pre-heated to 140 with a metal casting mold of the machine for centrifugal casting establish two profil rings of aluminum alloy, consisting of two parts. The plane of the connector of the rings passes through the center of the symmetry of the ring at an angle l 45 ° to the axis of symmetry OX (Fig. 1). The rings are fixed in shape, painted by their composition on the basis of paste Sch12, and the paint overlaps the joints of the rings. The mold is then installed in a centrifugal casting machine, the rotary actuator is turned on, other additional operations are performed, and cast iron is cast. The pouring temperature, pouring speed is 5-7 kg / s. After completion of pouring and holding in 20 min. Speed

no mold is gradually reduced to zero. Then the cast roll is allowed to cool to ZOO C, the mold is disassembled, and the forming rings are removed from the casting. In the roll thus obtained there are no cracks in gauges.

. When casting rolls with shaped rings, have a parting plane passing through the center O

 symmetry of the ring at an angle to the axis of symmetry OX (Fig. 1) oi 20 °, on three cast rolls of eight there were small hot longitudinal cracks on the parts of the barrel bordering on the gauge in the place where the sections of the profiling rings meet.

When casting rolls with profiling rings having a parting plane passing through the center of the symmetry of the ring at an angle to the axis of symmetry OX ci 40, all the rolls were obtained fit, without cracks.

When casting rolls with profiling rings having a parting plane passing through the center of the symmetry of the ring at an angle to the axis of symmetry OX eJ 50, all the rolls are fit, without cracks.

When casting rolls with profiling rings having a parting plane passing through the center. About the symmetry of the ring at an angle to the axis of symmetry OX oi 70 °, four transverse of eight cast rolls showed short transverse hot cracks in the bottom part of the stream. forming rings.

Claims (1)

Invention Formula A split forming ring to the mold for casting calibrated rolls consisting of two or more joined parts, characterized in that, in order to obtain high-quality calibrated rolls, the plane of the butt joints of the rings are made at an angle of 40-50 to the plane of axial symmetry of the ring. Fi9.1 f.2 Physical.ch