CN102836965A - Casting method for guaranteeing wall thickness precision of blast furnace hot-blast stove pillar - Google Patents

Abstract

The invention relates to the casting field of the blast furnace hot-blast stove pillar, particularly relates to a casting method for guaranteeing wall thickness precision of the blast furnace hot-blast stove pillar. The casting method comprises manufacture of exterior shape and a sand core, wherein two sides of the sand core is provided with a core print. The casting method is characterized in that a predeformation arc segment is arranged in the middle segment of the sand core corresponding to bending deformation amount in the in the middle segment of the sand core when pouring; and a calculation formula of maximum deflection fc of the horizontal center of the sand core is as follows: fc=5q14/384EI=5(F[buoyancy]-G[gravity])13/384EI. The core print is eccentric arranged in relative with the sand core; the central axis of the core print is higher than that of the sand core; the eccentricity b is 2 mm-4 mm, to balance out the deformation amount due to whole uplift of the sand core when pouring. Compared with a conventional method, the casting method provided by the invention has the beneficial effects that problems of wall thickness of a shell portion of the hot-blast stove pillar product becoming thinner and size over-tolerance caused by buoyancy force of molten iron are solved, allowing the wall thickness size precision of the cast hot-blast stove pillar product to reach technical requirements, so that a lot of waste is reduced.

Description

A kind of casting method that guarantees blast funnace hot blast stove pillar wall thickness accuracy

Technical field

The present invention relates to blast funnace hot blast stove pillar casting field, relate in particular to a kind of casting method that guarantees blast funnace hot blast stove pillar wall thickness accuracy.

Background technology

The blast funnace hot blast stove pillar is the main casting of hot-blast stove fire grate system, is used for carrying the fire grate and the checker brick heat storage of its top.At present both at home and abroad to be the middle part mostly be cartridge type, flanged (FLGD) form up and down to the blast funnace hot blast stove corbeling, and the pillar height is 1500～3500mm, diameter 250～400mm; Material is RTCr or RTCr2 mostly, wall thickness dimension tolerance 0～+ 3mm, its sand mold adopts cold-hardening resin sand to make; Do flat pouring technique production by flat, because the molten iron buoyancy function causes cold setresin core stage casing come-up; Make pillar stack shell position wall thickness one side attenuate, opposite side thickening, dimension overproof; Wall thickness is difficult to guarantee evenly, causes a large amount of waste products after the casting.And if employing upright casting process though can overcome the influence of buoyancy, makes the wall thickness dimension precision be able to guarantee, reduced operating efficiency, simultaneously waste material.

Summary of the invention

The purpose of this invention is to provide a kind of casting method that guarantees blast funnace hot blast stove pillar wall thickness accuracy; Overcome the deficiency of prior art; Revise sand core structure and size, overcome the influence of buoyancy, the hot-blast stove pillar product dimensional accuracy that casting is come out can reach specification requirement.

For solving the problems of the technologies described above, technical scheme of the present invention is:

A kind of casting method that guarantees blast funnace hot blast stove pillar wall thickness accuracy; Comprise the making of external form and core, the core both sides are provided with core print, according to the length of core; When making core box; The bending deformation quantity in core stage casing is provided with the reversible deformation segmental arc in its core stage casing during corresponding the cast, and the computing formula of the maximum defluxion fc of this segmental arc horizontal center is:

Fc=5ql ⁴/ 384EI=5 (F _Floating-G _Heavy) l ³/ 384EI;

In the formula: q is the uniform load that acts on the core, and unit is N/m;

L is a core length between two core prints, and unit is m;

E is the elastic modelling quantity of material, and unit is GN/m ²

I is the moment of inertia of core iron cross section, and unit is m ⁴

F _FloatingFor core receives the buoyancy of molten iron, unit is N;

G _HeavyBe the core deadweight, unit is N.

The relative core of said core print is eccentric to be provided with, and the core print central axis is higher than the core central axis, and its offset b is 2mm-4mm, and core is lifted the deflection that causes on the whole when offsetting cast.

Compared with prior art; The invention has the beneficial effects as follows: when having solved pouring molten iron, since the hot-blast stove pillar product stack shell position wall thickness attenuation that molten iron buoyancy causes, the problem of dimension overproof; The hot-blast stove pillar product wall thickness dimension precision that casting is come out can reach specification requirement; Reduced a large amount of waste products, improved production efficiency, realized energy-saving and cost-reducing.

Description of drawings

Fig. 1 is a blast funnace hot blast stove pillar product casting condition sketch map of the present invention;

Fig. 2 is a sand core structure sketch map of the present invention;

Fig. 3 is the left view of Fig. 2.

Among the figure: 1-core 2-pillar body 3-external form 4-injects mouth of a river 5-core print

The specific embodiment

Below in conjunction with specific embodiment the present invention is described further:

See Fig. 1; Be blast funnace hot blast stove pillar product pouring procedure sketch map of the present invention, adopt the conventional flat flat pouring technique of doing, comprise the making of external form and core; The core both sides are provided with core print; Core 1 is positioned at the heart portion of pillar body 2, pillar body 2 outside external forms 3 for the cold-hardening resin sand making, and external form stack shell middle part is established and is injected the mouth of a river 4.Treat molding sand sclerosis back lift, swabbing, manufactured the external form die cavity.The core 1 of the ready-made cold-hardening resin sand of system is put in the outer sand mold die cavity.The sand mold up and down of external form adopts alignment pin location and fixing, improves positioning accuracy.

See Fig. 2, in order to guarantee blast funnace hot blast stove pillar wall thickness accuracy, according to the length of core; When making core box; The bending deformation quantity in core stage casing is provided with the reversible deformation segmental arc in its core stage casing during corresponding the cast, and the computing formula of the maximum defluxion fc of this segmental arc horizontal center is: fc=5ql ⁴/ 384EI=5 (F _Floating-G _Heavy) l ³/ 384EI;

In the formula: q is the uniform load that acts on the core, and unit is N/m; L is a core length between two core prints, and unit is m; E is the elastic modelling quantity of material, and unit is G N/m ²I is the moment of inertia of core iron cross section, and unit is m ⁴F _FloatingFor core receives the buoyancy of molten iron, unit is N; G _HeavyBe the core deadweight, unit is N.

As when the core iron material adopts spheroidal graphite cast-iron, core iron diameter 100mm, core diameter 248mm, core length 3000mm between two core prints, F _FloatingFor core receives the buoyancy of molten iron is 10578 N; G _HeavyFor the core deadweight is 4038 N, spheroidal graphite cast-iron E is taken as 160G N/m ², the moment of inertia I=Л d4/64=4.9087x10 in core iron cross section ^-6m ⁴, the amount of deflection fc of core mid point is calculated as:

Fc=5 * (F _Floating-G _Heavy) l ³/ 384EI=5 (10578-4038) 3 ³/ 384 * 160 * 10 ⁹* 4.9087x10 ^-6=2.93mm.

See Fig. 3, core print 5 relative core 1 eccentric settings, core print 5 central axis are higher than core 1 central axis, and its offset b is 2mm-4mm, and core is lifted the deflection that causes on the whole when offsetting cast.Core print 5 bottoms are square, convenient location.

Claims (2)

1. a casting method that guarantees blast funnace hot blast stove pillar wall thickness accuracy comprises the making of external form and core, and the core both sides are provided with core print; It is characterized in that; According to the length of core, when making core box, the bending deformation quantity in core stage casing during corresponding the cast; In its core stage casing the reversible deformation segmental arc is set, the computing formula of the maximum defluxion fc of this segmental arc horizontal center is:

Fc=5ql ⁴/ 384EI=5 (F _Floating-G _Heavy) l ³/ 384EI;

In the formula: q is the uniform load that acts on the core, and unit is N/m;

L is a core length between two core prints, and unit is m;

E is the elastic modelling quantity of material, and unit is GN/m ²

I is the moment of inertia of core iron cross section, and unit is m ⁴

F _FloatingFor core receives the buoyancy of molten iron, unit is N;

G _HeavyBe the core deadweight, unit is N.

2. according to claims 1 described a kind of casting method that guarantees blast funnace hot blast stove pillar wall thickness accuracy; It is characterized in that; The relative core of said core print is eccentric to be provided with; The core print central axis is higher than the core central axis, and its offset b is 2mm-4mm, and core is lifted the deflection that causes on the whole when offsetting cast.

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