CN112719686A - Flat welding rod for welding and repairing circular saw blade crack - Google Patents
Flat welding rod for welding and repairing circular saw blade crack Download PDFInfo
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- CN112719686A CN112719686A CN202011497268.2A CN202011497268A CN112719686A CN 112719686 A CN112719686 A CN 112719686A CN 202011497268 A CN202011497268 A CN 202011497268A CN 112719686 A CN112719686 A CN 112719686A
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- welding
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
- B23K35/0255—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in welding
- B23K35/0261—Rods, electrodes, wires
- B23K35/0266—Rods, electrodes, wires flux-cored
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Abstract
The invention discloses a flat welding electrode for welding and repairing cracks of a circular saw blade, which consists of a welding core and a coating coated on the surface of the welding core, wherein the section of the welding core is flat, the material of the welding core is H08Mn2MoA, and the coating is prepared from 36-40% of marble, 19-23% of fluorite, 1-3% of titanium dioxide, 6-9% of ferrotitanium, 1-2% of low-carbon ferromanganese, 3-5% of ferrosilicon, 3-5% of metal manganese, 3-5% of metal chromium, 1-2% of mica, 2-4% of ferromolybdenum, 2-5% of ferrovanadium, 2-4% of nickel powder and 2-4% of rare earth metal by weight percentage. The flat welding electrode provided by the invention has high strength, high toughness and excellent crack resistance, can meet the requirement that the color and luster of weld metal and a saw blade base material are similar, and is suitable for welding narrow-gap grooves.
Description
Technical Field
The invention relates to the technical field of welding, in particular to a flat welding rod for welding and repairing cracks of a circular saw blade.
Background
At present, the circular saw blade is widely applied to cutting processing of steel, aluminum, stone, wood and the like. Generally, the thickness of the circular saw blade is between 2.0mm and 17mm, and the diameter is between 300mm and 5200 mm; the circular saw blade is made of tool steel or spring steel. The circular saw blade is structurally characterized by large diameter and thin thickness, and the material of the circular saw blade is characterized by high strength, rigidity and hardness, high carbon content and alloy content, easy hardening and poor weldability.
As shown in fig. 1, due to the structural and material characteristics of the circular saw blade, penetrating cracks are easily generated at some parts of the circular saw blade during the heat treatment and leveling and shaping manufacturing processes, and the circular saw blade is scrapped due to the fact that the crack position of the cracks is uncertain and the length and shape of the cracks are irregular.
The welding technology can repair the cracks of the circular saw blade, but the following technical requirements are met:
(1) the welding strength cannot be lower than that of the base material of the circular saw blade.
(2) Ensuring that the weld cannot crack and produce any defects that affect quality.
(3) The repaired welding seam metal has the color similar to that of a circular saw blade matrix.
According to the uncertainty of the crack position of the circular saw blade, the length of the crack and the particularity of the shape irregularity, the manual arc welding of the welding electrode has the absolute advantages of flexible and convenient operation and low welding cost, and is more suitable for welding repair of the crack of the circular saw blade than automatic welding.
According to the technical requirements of welding repair, the selected welding rod firstly meets the requirement that the color of the welding metal is similar to that of the saw blade matrix, secondly meets the index that the welding strength is higher than the saw blade material strength, thirdly has good crack resistance, and according to the information inquiry and the market information collection, the types of the welding rods which can achieve high strength, good toughness and good crack resistance are not many at present, and the representative welding rods such as J807RH, J857RH and J107Cr welding rods and the patent CN1241711C high manganese steel welding rod belong to ultralow-hydrogen high-toughness low-alloy structural steel welding rods which have high strength and toughness, but because of more colored alloy elements added in the welding rods, the color of the welding metal and the saw blade matrix still has large contrast, the welding rod does not meet the technical requirements of saw blade crack repair, the novel welding rod introduced in the patent CN 101368 is suitable for the special welding rod for assembling and welding large-diameter saw blades, the welding rod meets the technical indexes of saw blade welding in the aspects of mechanical property and color, but welding cracks are often generated in the welding repair process of saw blade cracks, and the analysis shows that the welding rod of the patent CN101362258 is welded under the condition of free openness, as shown in figure 2; the weld for repairing the crack of the circular saw blade is welded under the condition of closed constraint, and is shown in figure 3. As is known to all, in the welding and cooling process, a welding seam shrinks to generate certain tensile stress F, for open welding of a straight seam, two spliced and welded saw blade base metals can be freely pulled by the shrinkage stress, so that the stress of a welding joint can be released, and the welding is not easy to crack; for the welding of the circular saw blade cracks, welding seams are welded in a closed and restrained state of a saw blade base metal, stress generated in the welding process is released without places and is accumulated in a welding joint, so that the welding is easy to crack, and at present, no welding electrode product which can be used for repairing the circular saw blade cracks made of tool steel and spring steel exists.
According to three major factors generated by cold cracking: the analysis results show that the key for solving the generation of the welding cracks of the circular saw blade lies in reducing the hardened tissues and the restraint stress of the welding seams, the narrow gap welding can effectively reduce the welding seams, thereby reducing the welding heat input quantity, obviously reducing the hardened tissues and the restraint stress of the welding seams, and being an effective way for reducing the crack sensitivity, and the patent CN201510487598.6 introduces a flat welding rod with the narrow gap welding function, which meets the conditions of the narrow gap welding repair of the cracks of the circular saw blade, but does not meet the technical requirements of the circular saw blade crack welding repair in the aspects of mechanical property and color.
Disclosure of Invention
The invention aims to solve the technical problem of providing a flat welding rod for welding and repairing the cracks of a circular saw blade, which has high strength, high toughness and good crack resistance, can meet the requirement that the color of weld metal is similar to that of a saw blade base material, and is suitable for narrow-gap groove welding.
The technical scheme adopted by the invention for solving the technical problems is as follows:
the flat welding electrode for welding and repairing the cracks of the circular saw blade comprises a welding core and a coating coated on the surface of the welding core, wherein the cross section of the welding core is flat, the material of the welding core is H08Mn2MoA, and the coating is prepared from 36-40% of marble, 19-23% of fluorite, 1-3% of titanium dioxide, 6-9% of ferrotitanium, 1-2% of low-carbon ferromanganese, 3-5% of ferrosilicon, 3-5% of metal manganese, 3-5% of metal chromium, 1-2% of mica, 2-4% of ferromolybdenum, 2-5% of ferrovanadium, 2-4% of nickel powder and 2-4% of rare earth metal in percentage by weight.
In the component range of the welding rod coating composition, the ultralow-hydrogen high-toughness flat welding rod with similar color and luster of weld metal and a circular saw blade matrix, the tensile strength of deposited metal of 850-900 MPa, the content of diffused hydrogen of the weld joint of less than or equal to 1.0mL/100g, and no crack generated in the circular saw blade during welding repair at the preheating temperature of 100 ℃ can be manufactured by adjusting the formula proportion of the coating.
The chemical components of the composition in the coating of the welding rod and the effects of the components in the welding rod are shown in a table I, and the components can play several roles in the coating at the same time.
TABLE I chemical composition of components of coating for flat electrodes and its use in electrodes
Compared with the prior art, the welding electrode adopting the technical scheme has the beneficial effects that:
(1) the welding rod structure is flat, as shown in fig. 4 and fig. 5, is suitable for welding narrow gap grooves, such as flat welding rods with the specification of 2mm × 4mm (the sectional area is equivalent to a round rod-shaped welding rod with the specification of phi 3.2 mm), the welding groove is 5 mm-6 mm, and the welding groove needs 10mm, the narrow gap groove can obviously reduce the filling amount of welding meat and the welding heat input amount, thereby effectively reducing the hardening structure and the shrinkage stress of a welding seam, having the effects of obviously reducing the sensitivity of welding crack cracking, being beneficial to reducing the welding preheating temperature, leading the welding operation to be as simple as common welding, being feasible, reducing the groove, saving the using amount of welding materials and shortening the welding repair period.
(2) By selecting the H08Mn2MoA high-strength core wire and adjusting the proportion of the components in the chemical coating formula, the tensile strength of the deposited metal of the welding rod is finally 850-900 MPa, and the welding repair of the saw blade cracks with various material strength levels can be met.
(3) The welding rod has the characteristics of high plasticity and toughness and low content of diffused hydrogen, and is beneficial to avoiding the generation of welding cracks.
(4) By adjusting the proportion of alloy elements such as manganese, chromium, ferromolybdenum, ferrovanadium and nickel powder in the coating, the color of the weld metal is kept similar to that of the base material of the circular saw blade.
(5) The flat welding rod fills the blank of welding rods used for welding and repairing the cracks of the circular saw blade made of tool steel and spring steel, can be used for welding the cracks of the saw blade and welding components made of the same material, and therefore has high practical value and certain economic benefit and social significance.
Drawings
FIG. 1 is a schematic view of a circular saw blade and crack progression;
FIG. 2 is a schematic view of a weld in a free open condition;
FIG. 3 is a schematic view of a weld under closed restraint conditions;
FIG. 4 is a schematic view of a flat electrode;
FIG. 5 is a schematic view of welding of a flat electrode at a narrow gap groove;
FIG. 6 is a schematic top view of a circular saw blade crack weld repair;
FIG. 7 is a schematic front view of a circular saw blade for crack welding repair;
FIG. 8 is a schematic view of welding repair of a double U-shaped welding groove.
In the figure: the welding method comprises the following steps of 1, 2 cracks, 3 crack-stopping holes, 4 welding grooves, 5 flat welding electrodes, 51 welding cores, 52 coatings, 6 electric heating clamping tools, 7 heat-preservation covers, 8 welding seams, 10 backing welding seams, 11 filling welding seams, 12 cover welding seams, 13
Detailed Description
In order to make the technical solution of the present invention better understood by those skilled in the art, the following detailed description of the present invention will be made with reference to the accompanying drawings.
Referring to fig. 4 to 8, a flat welding electrode 5, which is composed of a core wire 51 and a coating 52 covering the core wire 51, was prepared by blending the ratio of the coating composition components in the range of the coating composition components of the electrode of the present invention as shown in table II below, and tests showed that the weld diffusion hydrogen content of examples 1 to 2 was not more than 1.0mL/100g, which is an ultra-low hydrogen electrode, and the mechanical properties of the electrode were as shown in table III below.
TABLE II composition of coating composition for flat welding electrode
TABLE III mechanical Properties of the deposited Metal of the Flat electrode
The preparation method of the flat welding rod 5 comprises the following steps:
(1) the components of the coating are proportioned, and the proportioned materials are poured into a stirrer to be mixed and stirred with dry materials.
(2) After the ingredients are mixed and stirred uniformly, 18 to 25 weight percent of water glass is added, and then wet stirring is carried out.
The water glass binder is prepared by mixing potassium silicate and sodium silicate according to the mass ratio of 4: 1.
(3) And pressing the uniformly stirred coating mixture into a material cylinder of a press coating device after briquetting, adjusting the wire feeding speed and the eccentricity of a press coating die to start press coating, and automatically finishing the grinding head, tail grinding, printing and drying of the welding rod in the press coating process.
As shown in FIG. 4, the cross section of the core wire 51 is flat, the material is H08Mn2MoA, the specification of the welding rod is set as the thickness multiplied by the width of the cross section of the core wire, the specification of the flat welding rod can be automatically determined according to the welding process requirements, according to the narrow groove characteristic of the saw blade crack welding repair, the specification of the welding rod of the embodiment of the invention is designed as 2mm multiplied by 4mm (the cross section area is equivalent to a round rod-shaped welding rod with phi 3.2 mm), the flat welding rod with the specification can be well welded in a welding groove with the width of 5 mm-6 mm, the welding groove width of the round rod-shaped welding rod with the same specification of phi 3.2mm is required to be at least more than 10mm, the reduction of the groove effectively reduces the hardening tissue and the shrinkage stress of the welding line, and the effect is that the sensitivity of the.
The circular saw blade crack welding repair is carried out by adopting the flat welding rod 5 in the two embodiments, as shown in fig. 5 to 8, the circular saw blade crack welding repair of two materials with the thickness of 10mm and the diameter of phi 3600mm is taken as an example, wherein the welding rod in the embodiment 1 is used as the circular saw blade material which is spring steel, the welding rod in the embodiment 2 is used as the circular saw blade material which is tool steel, a direct current welding machine is selected, the polarity is reversed, and the circular saw blade crack welding repair process comprises the following steps:
(1) derusting and deoiling: the steel wire brush is adopted to clean the periphery of the crack 2 of the circular saw blade 1 within 100mm, and dirt which influences the welding quality such as oil rust and the like cannot exist.
(2) Drilling a crack stop hole: and a drill bit with the diameter of 6mm is adopted to drill a crack stop hole 3 at the end of the crack 2, and the crack stop hole 3 can effectively prevent the end of the crack from extending and expanding.
(3) And (3) grinding a groove: and (3) polishing and welding a groove 4 along the trend of the crack 2 by adopting an angle polishing grinder, wherein the groove 4 is in a double-sided symmetrical U shape, the opening width of the groove is 6mm, and the thickness of the truncated edge is 1.5 mm.
(4) Preheating the circular saw blade: the circular saw blade is placed on an electric heating mould 6, the electric heating mould 6 is also a welding mould, a heat preservation quilt 7 is used for covering the circular saw blade 1, then a heat preservation cover 8 is covered for preheating, the preheating temperature is 100 ℃, the heat preservation is carried out for 2 hours, an opening is reserved at the crack 2 part of the heat preservation quilt 7, and a wide seam can be uncovered for facilitating welding construction.
(5) The welding process comprises the following steps:
a. the heat preservation cover 8 is removed, the heat preservation quilt 7 on the crack repairing part is uncovered by a seam, the heat preservation quilt 7 is covered by other parts continuously, and the electric heating mould 6 keeps a continuous heating state.
b. Point fixing welding: the flat welding electrode 5 is adopted to perform segmented spot welding on the gap of the root part of the welding groove 4 firmly, the length of a spot welding seam is 10-15 mm, and the two ends of the welding seam are firmly subjected to spot welding.
c. Backing welding: and backing welding is carried out on the welding groove by adopting a flat welding electrode 5, and a backing welding seam 11 is welded by adopting a single-side welding back forming and intermittent welding mode.
d. Filling and welding: and filling and welding the welding groove by using the flat welding electrode 5, fully welding the filling welding line 12 at one time in an intermittent welding mode, firstly fully welding the welding lines at two ends, then welding the middle part, and hammering the filling welding line after welding to eliminate welding stress.
e. And (3) cover surface welding: and (3) performing cover welding on the welding seam groove by using the flat welding electrode 5, welding the cover welding seam 13 in a continuous welding mode, wherein the surplus height of the cover welding seam is less than 1.5mm, the defects of undercut and pits are not allowed to exist, and hammering the cover welding seam after welding to eliminate welding stress.
f. Welding the back of the turnover circular saw blade: and (e) after one surface is welded, welding the other surface by hoisting and overturning the circular saw blade 1, removing welding beading, welding slag and incomplete penetration defects of a back backing weld by using a grinding wheel, filling and welding according to the step d, and performing cover surface welding according to the step e.
(6) Circular saw blade heat preservation slow cooling: and covering the welded circular saw blade 1 with a heat preservation cover 8 for heating and heat preservation, stopping heating after the temperature is heated to 100 ℃, and then cooling to room temperature along with the furnace.
(6) Polishing the welding line: and polishing, repairing and flattening the weld joints on the front side and the back side.
(8) Quality inspection: and (4) carrying out flaw detection on the repaired welding seam by using ultrasonic waves, and judging that the repaired welding seam is qualified if any defect is not found.
The welded circular saw blade is tested, the surface of the welding seam is smooth and flat, the performance index of the welding seam accords with the technical index requirement of circular saw blade crack welding repair, the color of the welding seam metal is close to that of the circular saw blade metal, the welding seam has high plasticity and toughness, and the normal welding does not generate cracks under the condition of 100 ℃, so that the problem of overhigh preheating temperature is effectively solved, and meanwhile, the welding operation is as simple, convenient and feasible as the common welding.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (2)
1. The utility model provides a platykurtic welding rod for welding repair circular saw piece crackle, comprises core wire and the coating of cladding on the core wire surface, its characterized in that: the cross section of the welding core is flat, the material of the welding core is H08Mn2MoA, and the coating is prepared from 36-40% of marble, 19-23% of fluorite, 1-3% of titanium dioxide, 6-9% of ferrotitanium, 1-2% of low-carbon ferromanganese, 3-5% of ferrosilicon, 3-5% of manganese metal, 3-5% of chromium metal, 1-2% of mica, 2-4% of ferromolybdenum, 2-5% of ferrovanadium, 2-4% of nickel powder and 2-4% of rare earth metal by weight percentage.
2. The flat welding electrode for welding repair of cracks in a circular saw blade according to claim 1, wherein: in the component range of the welding rod coating composition, the ultralow-hydrogen high-toughness flat welding rod with similar color and luster of welding seam metal and a circular saw blade matrix, the tensile strength of deposited metal of 850-900 MPa, the content of diffused hydrogen of welding seams of less than or equal to 1.0mL/100g and no crack generated in the circular saw blade during welding repair at the preheating temperature of 100 ℃ is manufactured by adjusting the formula proportion of the coating.
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Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1056171A (en) * | 1961-10-07 | 1967-01-25 | Tsnii T I Mashinostrojenija | An electrode for electric arc welding and surfacing of grey and high-strength cast iron |
CN1148529A (en) * | 1995-10-24 | 1997-04-30 | 李向荣 | Preheating-free high anti-cracking surfacing welding electrode |
CN1439477A (en) * | 2003-01-22 | 2003-09-03 | 哈尔滨工业大学 | Flat electrodes |
CN1827288A (en) * | 2006-04-12 | 2006-09-06 | 西华大学 | Bainite welding rod dedicated for repairing rail and assembled frog |
CN101362258A (en) * | 2008-09-25 | 2009-02-11 | 哈尔滨工业大学 | Novel electric welding rod |
CN105033507A (en) * | 2015-09-22 | 2015-11-11 | 山东大学 | Special-purpose welding rod for built-up welding of hot work die restoration |
-
2020
- 2020-12-17 CN CN202011497268.2A patent/CN112719686A/en active Pending
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1056171A (en) * | 1961-10-07 | 1967-01-25 | Tsnii T I Mashinostrojenija | An electrode for electric arc welding and surfacing of grey and high-strength cast iron |
CN1148529A (en) * | 1995-10-24 | 1997-04-30 | 李向荣 | Preheating-free high anti-cracking surfacing welding electrode |
CN1439477A (en) * | 2003-01-22 | 2003-09-03 | 哈尔滨工业大学 | Flat electrodes |
CN1827288A (en) * | 2006-04-12 | 2006-09-06 | 西华大学 | Bainite welding rod dedicated for repairing rail and assembled frog |
CN101362258A (en) * | 2008-09-25 | 2009-02-11 | 哈尔滨工业大学 | Novel electric welding rod |
CN105033507A (en) * | 2015-09-22 | 2015-11-11 | 山东大学 | Special-purpose welding rod for built-up welding of hot work die restoration |
Non-Patent Citations (1)
Title |
---|
董强等: "《电焊工》", 30 April 2007 * |
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Effective date of registration: 20211109 Address after: 276500 Jingjia Honggou village, Honggou community, Qiaoshan Town, Ju county, Rizhao City, Shandong Province Applicant after: Rizhao tangsheng sawing Co.,Ltd. Address before: 064102 2 km west of yahongqiao Town, Yutian County, Tangshan City, Hebei Province Applicant before: HEBEI SINGSHUO SAW Co.,Ltd. |
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