CN106475661A - A surfacing welding process for wear-resistant grinding tiles - Google Patents

Abstract

The invention relates to a surfacing process of a wear-resistant grinding disc tile, which comprises the following steps: firstly, arranging grinding disc tile lining plates: 4 grinding disc tile lining plates are distributed and positioned by 4 wedge-shaped bolts; determining the section size of the grinding disc; preparing the grinding disc tile before welding; fourthly, overlaying a grinding wheel working layer: controlling the temperature of the processed grinding disc to be not more than 100 ℃, and carrying out multilayer surfacing on the processed grinding disc by adopting a ceramic wear-resistant surfacing electrode under the normal temperature condition; fifthly, cutting and forming: and cutting the grinding disc into single blocks according to the number by adopting plasma cutting, cleaning the surface splash and flash burrs generated by cutting, confirming the size, and entering a machining sequence to finish the product processing. The invention has simple process and easy implementation, and the build-up welding thickness can reach 32mm through multilayer build-up welding and can ensure that the block does not fall off after long-term working under the working conditions of abrasion and impact.

Description

A surfacing welding process for wear-resistant grinding tiles

technical field

The invention relates to the technical field of wear-resistant surfacing welding, in particular to a surfacing process of wear-resistant grinding disc tiles.

Background technique

In the coal pulverization system, how to prolong the service life of the wearing parts of the pulverization equipment and reduce the maintenance cost has become an important way for enterprises to further improve economic benefits. Taking the medium-speed coal mill of the coal grinding system as an example, as the main wearing part of the grinding disc, in order to improve its wear resistance and impact resistance, the material of the grinding disc tile is usually cast steel of various brands, even if the high chromium cast iron composite grinding disc tile is used , and its service life is only 8000~10000 hours. Therefore, the low life of the grinding disc has always been the key factor restricting the performance of the coal grinding system.

With the application of hard surface surfacing technology, various coal grinding and pulverizing enterprises have adopted the surfacing remanufacturing technology based on wear-resistant electrodes and welding wires, which has improved the wear resistance of the grinding tiles to a certain extent and prolonged the use of the grinding tiles. life. However, the existing wear-resistant surfacing technology mainly increases the hardness of the surfacing metal layer by adding tungsten carbide particles or increasing the carbon content and other alloys. There are generally high carbon equivalents, low plasticity, low impact resistance, and easy peeling (dropping blocks) )And other issues. Therefore, the existing wear-resistant surfacing grinding tile generally has the problems of thin surfacing metal layer, poor reliability, and still low service life. In addition, the use of the existing high-chromium cast iron surfacing wear-resistant tiles is limited to castings with an effective cross-section of 100-140 mm due to the utilization of the high-chromium cast iron metal layer. Through practical operation, it is a waste of high-performance materials for the entire wear-resistant casting, which not only increases production and operation costs, but also improper utilization of high-chromium cast iron metal resources.

Therefore, in view of the current situation that the material of the grinding disc of coal grinding equipment is usually various grades of high manganese steel and cast steel, combined with high manganese steel and cast steel substrates suitable for welding and surfacing welding of various grades, the thickness of the surfacing layer can be adjusted. Up to 32mm, a ceramic wear-resistant surfacing electrode with a metal hardness of the surfacing layer up to HRC75. Based on a specific surfacing process, an innovative double-layer metal wear-resistant grinding disc tile is formed to achieve a long life (the service life is as high as that of a high-chromium cast iron grinding disc tile. 1.8~2.5 times of that) grinding disc preparation has important practical significance and broad application prospects.

Contents of the invention

The technical problem to be solved by the present invention is to provide a simple process and easy-to-implement wear-resistant grinding tile surfacing process.

In order to solve the above problems, a surfacing welding process of a wear-resistant grinding disc tile according to the present invention comprises the following steps:

⑴Mopan tile lining board layout: 4 mopan tile lining board layouts are adopted, and are positioned by 4 wedge bolts;

(2) Use the following formula to determine the cross-sectional size of the millstone: H=h+2% D+20mm; where: H is the height of the millstone tile determined by surfacing welding repair, in mm; h is the original designed height dimension of the worn millstone tile, in units mm; D is the diameter of the grinding roller, in mm;

⑶Preparation for grinding tile welding:

① After cleaning the worn working surface of the grinding disc, use the penetrant flaw detection method to detect the cracks in the grinding disc. After the cracks of the grinding disc tile are smoothed, use ultrasonic flaw detection to detect the crack depth. If the crack depth exceeds 1/4 of the wall thickness, scrap the grinding disc; if The crack depth is less than 1/4 of the wall thickness, and the crack is ground and repaired with J506 welding rod;

②Confirm the number of each grinding disc, assemble and fix it on the positioner according to the number;

⑷ Surfacing of the working layer of the grinding disc: control the temperature of the treated grinding disc to not exceed 100°C, and use ceramic wear-resistant surfacing electrodes to perform multi-layer surfacing welding on the treated grinding disc under normal temperature conditions;

⑸Cutting and forming:

Using plasma cutting, the grinding disc is cut into single pieces according to the number, the surface splash and the flash burrs generated by cutting are cleaned, the size is confirmed, and the product processing can be completed in the machining process.

In the step (4), the surfacing welding material is a ceramic wear-resistant surfacing electrode, and the diameter of the electrode is 3.2mm, 4.0mm, 5.0mm, including a welding core and a coating; the weight factor of the coating accounting for the total weight of the electrode is 0.40~0.48; where

The welding core is based on the total weight of the welding core, and its chemical composition is: C 2-4%, Cr 9-12%, Mn 1-2%, Nb 0.1-0.3%, Mo 0.3-1% , Ti 0.1~0.4%, V 0.1~1%, Si 0.2~1%, P ≤0.03%, S ≤0.04%, and the balance is Fe;

The drug skin is based on the total weight of the drug skin, and its chemical composition is calculated by weight percentage: 18-22% of marble, 15-20% of fluorite, 20-26% of mica+bentonite, 12-15% of rutile+titanium dioxide %, ferro-titanium 5-8%, ferro-manganese 5-8%, ferrosilicon 5-8%, ferro-chromium 3-6%, nickel 1-3%, rare earth oxide 1-3%.

In the described step (4), the multi-layer overlay welding condition refers to:

A When the diameter of the electrode is 3.2mm, the corresponding welding current is 110~150 amperes; when the diameter of the electrode is 4.0mm, the corresponding welding current is 160~200 amperes; when the diameter of the electrode is 5.0 mm, the corresponding welding current is 170~230 amps;

B voltage range is 20~28V;

C The grinding disc surface and the welding torch form a 15° climbing welding, and the distance between the grinding disc surface and the welding tip is 10~15mm;

D welding bead overlapping 45%~50%, welding bead width 8~14 mm;

The thickness of E surfacing alloy layer is 1~32mm.

Compared with the prior art, the present invention has the following advantages:

1. The present invention improves the layout of 12 millstone tile lining boards in the traditional millstone design to four millstone tile lining board layouts, which increases the weight of a single tile and enhances the fit between the tile and the millstone seat, improving the stability of the installation sex.

2. The increase of the arc of the raceway of the lining plate of the grinding disc and the improvement of the height dimension of the grinding disc tile and the arc dimension of the raceway in the present invention fully consider the requirements of the thickness of the material layer, the grindability of the material, the particle distribution, the water content and other factors on the performance of the grinding disc.

3. The ceramic wear-resistant surfacing electrode in the present invention contains ceramics, titanium, chromium, manganese, molybdenum, vanadium, niobium, etc., so that the microstructure of the material surfacing layer metal is very delicate, and the wear-resistant phase is uniform and dense. The hexagonal structure forms quite stable and hard carbides, which makes the metal of the surfacing layer have high hardness (the initial hardness after welding can reach HRC68, and the hardness after use can reach HRC75), excellent wear resistance and corrosion resistance (melting The metallization contains chromium, nickel and other elements, so that the surfacing layer has a certain corrosion resistance).

4. The invention does not require preheating during welding, and can be used for both AC and DC, with stable welding arc, less spatter, and easy slag removal. Through multi-layer surfacing welding, the thickness of surfacing welding can reach 32mm and can ensure that the block will not fall off for a long time under the conditions of wear and impact.

5. The process of the present invention is simple and easy to implement.

Description of drawings

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Fig. 1 is a cross-sectional size diagram of the surfacing grinding disc of the present invention.

detailed description

A surfacing welding process for wear-resistant grinding tiles, comprising the following steps:

⑴Mopan tile lining board layout: 4 mopan tile lining board layouts are adopted, and are positioned by 4 wedge bolts.

(2) Use the following formula to determine the height of the disc section: H=h+2% D+20mm (see Figure 1); where: H is the height of the disc tile determined by surfacing repair, in mm; h is the worn disc tile The height dimension of the original design, in mm; D is the diameter of the grinding roller, in mm; in addition, R in Figure 1 is the radius of curvature of the raceway determined according to the actual size of the worn grinding tile during surfacing repair, and t is determined by surfacing repair The thickness dimension of the surfacing alloy layer of the grinding tile.

⑶Preparation for grinding tile welding:

① After cleaning the worn working surface of the grinding disc, use the penetrant flaw detection method to detect the cracks in the grinding disc. After the cracks of the grinding disc tile are smoothed, use ultrasonic flaw detection to detect the crack depth. If the crack depth exceeds 1/4 of the wall thickness, scrap the grinding disc; if The crack depth is less than 1/4 of the wall thickness, and the crack is ground and repaired with J506 welding rod;

②Confirm the number of each grinding disc, assemble and fix it on the positioner according to the number.

⑷ Surfacing welding of the working layer of the grinding disc: control the temperature of the processed grinding disc to not exceed 100°C, and use ceramic wear-resistant surfacing electrodes to carry out multi-layer surfacing welding on the treated grinding disc under normal temperature conditions.

The surfacing welding consumables are ceramic wear-resistant surfacing electrodes, the diameters of which are 3.2mm, 4.0mm, and 5.0mm, including the welding core and coating; the weight coefficient of the coating accounting for the total weight of the electrode is 0.40~0.48;

The welding core is based on the total weight of the welding core, and its chemical composition is: C 2~4%, Cr 9~12%, Mn 1~2%, Nb 0.1~0.3%, Mo 0.3~1%, Ti 0.1~0.4%, V 0.1~1%, Si 0.2~1%, P ≤0.03%, S ≤0.04%, the balance is Fe;

The drug skin is based on the total weight of the drug skin. In terms of weight percentage, its chemical composition is: marble 18~22%, fluorite 15~20%, mica+bentonite 20~26%, rutile+titanium dioxide 12~15%, Ferro-titanium 5~8%, ferromanganese 5~8%, ferrosilicon 5~8%, ferrochromium 3~6%, nickel 1~3%, rare earth oxide 1~3%.

The preparation method of the ceramic wear-resistant surfacing welding electrode adopts the traditional process, namely: welding core grinding to remove rust, straightening → dry mixing powder → adding water glass wet mixing → using wet powder to rub the welding rod on the welding core → drying the welding rod Dry in the oven → product inspection.

Multi-layer surfacing conditions refer to:

A When the diameter of the electrode is 3.2mm, the corresponding welding current is 110~150 amperes; when the diameter of the electrode is 4.0mm, the corresponding welding current is 160~200 amperes; when the diameter of the electrode is 5.0 mm, the corresponding welding current is 170~230 amps;

B voltage range is 20~28V;

C The grinding disc surface and the welding torch form a 15° climbing welding, and the distance between the grinding disc surface and the welding tip is 10~15mm;

D welding bead overlapping 45%~50%, welding bead width 8~14 mm;

The thickness of E surfacing alloy layer is 1~32mm.

⑸Cutting and forming:

Using plasma cutting, the grinding disc is cut into single pieces according to the number, the surface splash and the flash burrs generated by cutting are cleaned, the size is confirmed, and the product processing can be completed in the machining process.

Example 1 The welding base material is the grinding disc of MPF1915 roller-disc medium-speed coal mill (material is ZG25) of JISCO Hongda Cement Plant, the multi-layer surfacing layer is 4 layers, and the electrode diameter of the first layer is 4.0mm , the welding current is 124 amps, the welding voltage is 24V; the electrode diameter of the other layers is 5.0mm, the welding current is 180 amps, the welding voltage is 32V; the weld bead width is 10~11mm, the temperature between welding layers is 86~96°C, The average thickness of the welding layer is 22mm. After welding, the hardness reaches HRC68, and after one month of use, the hardness reaches HRC75, and there is no falling block.

Example 2 The welding base material is the grinding disc of the MPF1713 roller-disk medium-speed coal mill (material is ZG25) of JISCO Hongda Cement Plant, the multi-layer surfacing layer is 4 layers, and the electrode diameter of the first layer is 3.2mm , the welding current is 115 amps, the welding voltage is 22V; the electrode diameter of the other layers is 4.0mm, the welding current is 128 amps, the welding voltage is 26V; the weld bead width is 9.5~10.5mm, and the temperature between welding layers is 83~95°C. The average thickness of the surfacing layer is 20mm. After welding, the hardness reaches HRC67, and after one month of use, the hardness reaches HRC74, and there is no block.

In above-mentioned embodiment 1～2, electrode is ceramic wear-resisting surfacing welding electrode, comprises welding core and coating; The weight factor that coating accounts for electrode gross weight is 0.45; Wherein

The welding core is based on the total weight of the welding core, and its chemical composition is: C 2.46%, Cr 11.3%, Mn1.32%, Nb 0.132%, Mo 0.468%, Ti 234%, V 0.264%, Si 0.65%, P 0.021%, S 0.023%, the balance is Fe;

The drug skin is based on the total weight of the drug skin, and its chemical composition is: 20% marble, 17% fluorite, 23% mica + bentonite, 13% rutile + titanium dioxide, 7% ferro-titanium, 6% ferromanganese %, ferrosilicon 6%, ferrochrome 4%, nickel 2%, rare earth oxide 2%.

It should be understood that the examples and implementations discussed here are for illustration only, and that various improvements and changes can be proposed by those skilled in the art, and these improvements and changes will be included in the spirit and scope of the present application and the scope of the appended claims Inside.

Claims (3)

1. A surfacing process for wear-resistant grinding disc tiles, comprising the following steps: ⑴Mopan tile lining board layout: 4 mopan tile lining board layouts are adopted, and are positioned by 4 wedge bolts; (2) Use the following formula to determine the cross-sectional size of the millstone: H=h+2% D+20mm; where: H is the height of the millstone tile determined by surfacing welding repair, in mm; h is the original designed height dimension of the worn millstone tile, in units mm; D is the diameter of the grinding roller, in mm; ⑶Preparation for grinding tile welding: ① After cleaning the worn working surface of the grinding disc, use the penetrant flaw detection method to detect the cracks in the grinding disc. After the cracks of the grinding disc tile are smoothed, use ultrasonic flaw detection to detect the crack depth. If the crack depth exceeds 1/4 of the wall thickness, scrap the grinding disc; if The crack depth is less than 1/4 of the wall thickness, and the crack is ground and repaired with J506 welding rod; ②Confirm the number of each grinding disc, assemble and fix it on the positioner according to the number; ⑷ Surfacing of the working layer of the grinding disc: control the temperature of the treated grinding disc to not exceed 100°C, and use ceramic wear-resistant surfacing electrodes to perform multi-layer surfacing welding on the treated grinding disc under normal temperature conditions; ⑸Cutting and forming: Using plasma cutting, the grinding disc is cut into single pieces according to the number, the surface splash and the flash burrs generated by cutting are cleaned, the size is confirmed, and the product processing can be completed in the machining process. 2. the surfacing process of a kind of wear-resistant grinding disc tile as claimed in claim 1 is characterized in that: in the described step (4), the surfacing welding material is a ceramic wear-resistant surfacing electrode, and the diameter of this electrode is 3.2mm, 4.0mm, 5.0mm, including welding core and coating; the weight factor of the coating accounting for the total weight of the electrode is 0.40~0.48; where The welding core is based on the total weight of the welding core, and its chemical composition is: C 2-4%, Cr 9-12%, Mn 1-2%, Nb 0.1-0.3%, Mo 0.3-1% , Ti 0.1~0.4%, V 0.1~1%, Si 0.2~1%, P ≤0.03%, S ≤0.04%, and the balance is Fe; The drug skin is based on the total weight of the drug skin, and its chemical composition is calculated by weight percentage: 18-22% of marble, 15-20% of fluorite, 20-26% of mica+bentonite, 12-15% of rutile+titanium dioxide %, ferro-titanium 5-8%, ferro-manganese 5-8%, ferrosilicon 5-8%, ferro-chromium 3-6%, nickel 1-3%, rare earth oxide 1-3%. 3. The surfacing process of a kind of wear-resistant grinding disc tile as claimed in claim 1, is characterized in that: in the described step (4), the multi-layer surfacing condition refers to: A When the diameter of the electrode is 3.2mm, the corresponding welding current is 110~150 amperes; when the diameter of the electrode is 4.0mm, the corresponding welding current is 160~200 amperes; when the diameter of the electrode is 5.0 mm, the corresponding welding current is 170~230 amps; B voltage range is 20~28V; C The grinding disc surface and the welding torch form a 15° climbing welding, and the distance between the grinding disc surface and the welding tip is 10~15mm; D welding bead overlapping 45%~50%, welding bead width 8~14 mm; The thickness of E surfacing alloy layer is 1~32mm.