CN101934556A - Screw impeller of pouring stirrer and overlaying method thereof - Google Patents

Abstract

The invention discloses a screw impeller of a pouring stirrer and an overlaying method thereof. In the invention, a layer of wear resistant material is overlaid on the outer surface of a screw impeller of 16Mn steel, and the wear resistant material is overlaid by overlaying 65 type welding rods; and each overlaying 65 type welding rod comprises the following elements in percentage by weight: 2.5-4.5 percent of C, 13-16 percent of Cr, 1.5-2.0 percent of Mn, 1.0-1.5 percent of Si, 4.0-5.0 percent of W, 3.0-4.0 percent of B and the balance of Fe. The overlaying method comprises the following steps of: removing impurities such as rust, oil stains, and the like on the screw impeller of the 16Mn steel; heating the screw impeller to 250-300 DEG C; overlaying by adopting a short arc and low current, wherein the overlaying thickness is 3-5 millimeters; and beating welding spots by hands once one welding rod is used up. The service life of the screw impeller subjected to overlaying is 5 times as long as that of the traditional screw impeller of the 16Mn steel, thus the invention prolongs the service life, reduces the production cost and improves the production efficiency.

Description

A kind of cast mixer helical runner and overlaying method thereof

Technical field

The present invention relates to helical runner, relate in particular to a kind of air entrained concrete cast mixer helical runner.

Background technology

In order to make full use of the flyash that steam power plant produces, minimizing is to the pollution of environment, general using flyash is made the air entrained concrete brick and is used for building field, the stirring of flyash slip and other powder and the cast of mixed slurry are finished by the cast mixer, at present, cast mixer spiral cast mixer as shown in Figure 1 commonly used, this mixer have pot a shape bottom and the cylindrical shell that binds, agitator is a helical runner, is with the guide shell that is supported on barrel in the agitator outside.Material is entered by top, the slip that stirs by tube at the bottom of the discharge port at middle part discharge.This cast mixer is simple in structure, and result of use is good, and maintenance and cleaning are convenient.But because the agitator of helical runner is when rotating at a high speed, various materials in the air entrained concrete slip are done complicated fierce motion, fierce friction, collision, impact take place in the agitator of material and helical runner, quicken the wearing and tearing on helical runner surface, especially the edge abrasion of helical runner is faster, though cast mixer helical runner adopts wear-resisting 16Mn steel, but generally can only be with 2～3 months, and it is big to change difficulty, need 4 people's operations, be 7～8 hours man-hour, and time and effort consuming has increased production cost.Also need during replacing to stop work, influence production efficiency.

Summary of the invention

The present invention is the shortcoming and defect that overcomes existing cast mixer helical runner, and is provided a kind of helical runner service life of can prolonging, and reduces production costs the cast mixer helical runner of enhancing productivity.

The technical scheme that the present invention solves the problems of the technologies described above is:

A kind of cast mixer helical runner, its material is the 16Mn steel, at helical runner appearance built-up welding one deck high-abrasive material of described 16Mn steel.

Described high-abrasive material is formed by heap 65 type welding rod built-up welding.

The contained element wt percentage of described heap 65 type welding rods is respectively: C is 2.5～4.5%, and Cr is 13～15%, and Mn is 1.5～2.0%, and Si is 1.0～1.5%, and W is 4.0～5.0%, and B is 3.0～4.0%, and surplus is Fe.

A kind of overlaying method of pouring into a mould the mixer helical runner, its step is;

(1) the cast mixer helical runner to the 16Mn steel is removed impurity such as iron rust, greasy dirt before the weldering;

(2) helical runner is heated to 250 ℃～300 ℃;

(3) with heap 65 type welding rods all upper and lower surfaces to cast mixer helical runner, comprise that the impeller edge all wants built-up welding, adopt the little electric current welding of short electric arc during built-up welding, avoid the scaling loss of alloying element, when core diameter is 3.2 millimeters, welding current is 100～120A; When core diameter is 4.0 millimeters, welding current is 120～160A, and built-up welding thickness is 3～5 millimeters;

(4) beat solder joint with hand hammer behind the intact welding rod of every weldering, it is heated evenly, reach the good result of soldering.

Technique effect of the present invention is: through big quantity research and test, the 16Mn steel is obtained beyond thought wear-resisting effect with heap 65 type welding rod built-up welding, deposited metal hardness after the built-up welding is 65HRC, be 10～12 months the service life of built-up welding rear screw impeller, is 5 times of original 16Mn steel helical runner service life.Therefore, the present invention has prolonged the service life and the replacement cycle of helical runner, has reduced production cost, has improved production efficiency.

Description of drawings

Fig. 1 is spiral cast mixer cutaway view.

Among the figure, 1, helical runner, 2, cylindrical shell, 3, guide shell, 4, discharge port

The specific embodiment

The present invention describes in detail by embodiment:

A kind of cast mixer helical runner, its material are 16Mn steel (being the low-alloy high-tensile structural steel among the GB GB/T1591-1988, the Q345 among the corresponding GB GB/T1591-1994), the alloying component of 16Mn steel:

Carbon C:0.13～0.19%

Manganese Mn:1.20～1.60%

Nickel :≤0.30%

Silicon Si:0.20～0.60%

Phosphorus P :≤0.030%

Sulphur S :≤0.030%

Chromium Cr :≤0.30%

Copper Cu :≤0.25%

Helical runner appearance built-up welding one deck high-abrasive material at described 16Mn steel.Through big quantity research and research, described high-abrasive material adopts heap 65 type welding rod built-up welding to form.The contained element wt percentage of described heap 65 type welding rods is respectively:

Carbon C:2.5～4.5%

Chromium Cr:13～15%

Manganese Mn:1.5～2.0%

Silicon Si:1.0～1.5%

Tungsten W:4.0～5.0%

Boron: 3.0～4.0%

Surplus is iron Fe

Need before the weldering cast mixer helical runner is removed impurity such as iron rust, greasy dirt; Adopt the little electric current welding of short electric arc, avoid the scaling loss of alloying element, core diameter is 3.2 millimeters, and welding current is 100～120A; Core diameter is 4.0 millimeters, and welding current is 120～160A.Built-up welding thickness is 3～5 millimeters.To annotating all upper and lower surfaces of mixer helical runner, comprise that the impeller edge all wants built-up welding.

During welding, preferably helical runner is heated to 250 ℃～300 ℃, carries out comprehensive built-up welding with heap 65 type welding rods again, beat solder joint with hand hammer again behind the intact welding rod of every weldering, it is heated evenly, reach the good result of soldering.Piling 65 type welding rods is that graphite does not have the slag welding rod, and postwelding does not have slag substantially, so postwelding need not scarfing cinder built-up welding continuously, can significantly improve production efficiency, save welding rod, and manufacturability is good.This welding rod is the AC/DC welding rod, has very high anti-low stress abrasive wear performance.This welding rod only is suitable for single-layer surfacing.

Claims (4)

1. cast mixer helical runner, its material is the 16Mn steel, it is characterized in that: at helical runner appearance built-up welding one deck high-abrasive material of described 16Mn steel.

2. according to the described a kind of cast mixer helical runner of claim 1, it is characterized in that: described high-abrasive material is formed by heap 65 type welding rod built-up welding.

3. according to the described a kind of cast mixer helical runner of claim 2, it is characterized in that: the contained element wt percentage of described heap 65 type welding rods is respectively: C is 2.5～4.5%, Cr is 13～15%, Mn is 1.5～2.0%, Si is 1.0～1.5%, W is 4.0～5.0%, and B is 3.0～4.0%, and surplus is Fe.

4. an overlaying method of pouring into a mould the mixer helical runner is characterized in that step is;

(1) impurity such as iron rust, greasy dirt are removed on the cast mixer helical runner surface to the 16Mn steel before the weldering;

(2) will pour into a mould the mixer helical runner and be heated to 250 ℃～300 ℃;

(3) with heap 65 type welding rods all upper and lower surfaces to cast mixer helical runner, comprise that the impeller edge all wants built-up welding, adopt the little electric current welding of short electric arc during built-up welding, avoid the scaling loss of alloying element, when core diameter is 3.2 millimeters, welding current is 100～120A; When core diameter is 4.0 millimeters, welding current is 120～160A, and built-up welding thickness is 3～5 millimeters;

(4) beat solder joint with hand hammer behind the intact welding rod of every weldering, it is heated evenly, reach the good result of soldering.

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