CN102527999A - Edge welding casting repair process of grey iron casting - Google Patents

Edge welding casting repair process of grey iron casting Download PDF

Info

Publication number
CN102527999A
CN102527999A CN201110421481XA CN201110421481A CN102527999A CN 102527999 A CN102527999 A CN 102527999A CN 201110421481X A CN201110421481X A CN 201110421481XA CN 201110421481 A CN201110421481 A CN 201110421481A CN 102527999 A CN102527999 A CN 102527999A
Authority
CN
China
Prior art keywords
casting
iron casting
sand mold
temperature
welding
Prior art date
Application number
CN201110421481XA
Other languages
Chinese (zh)
Inventor
李培伟
张云蒙
杨金勇
Original Assignee
保定天威集团有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 保定天威集团有限公司 filed Critical 保定天威集团有限公司
Priority to CN201110421481XA priority Critical patent/CN102527999A/en
Publication of CN102527999A publication Critical patent/CN102527999A/en

Links

Abstract

The invention discloses an edge welding casting repair process of a grey iron casting, comprising the steps of: baking a cast iron electrode with a diameter of 5 mm and above at a temperature of 150-200 DEG C for 2-3 hours; making a sand mould outside a broken part of the grey iron casting by using moulding sand, melting the cast iron electrode in the sand mould by a current which is 55-65 times of the diameter of the electrode, and removing generated welding residues at the same time; continuously accumulating molten iron melted by the electrode until the whole sand mould is full; placing an electrothermal furnace around the sand mould for baking, controlling a temperature of the electrothermal furnace within 700-950 DEG C to ensure that the molten iron in the sand mould is gradually cooled, solidified and then formed into a whole with the original grey iron casting, keeping the temperature for 2-3 hours, turning off a power supply of the electrothermal furnace, and removing the electrothermral furnace and performing air cooling on the grey iron casting to the room temperature when the temperature of the grey iron casting is reduced to 500-550 DEG C; and removing the sand mould and machining and polishing the broken part to be repaired. According to the repair process provided by the invention, white cast iron formed at an edge welding part of the grey iron casting can be eliminated, mechanical machining property of a repair welding area of the grey iron casting is improved, the operation is simple and the effect is obvious.

Description

Gray iron casting edge welding casting repair technology

Technical field

The present invention relates to the repair by welding field, relate in particular to the repair technology that a kind of gray iron casting edge breakage welds casting afterwards.

Background technology

Casting pig is that a kind of production cost is low, and has the cast metal material of many superperformances, has obtained in plant equipment manufacturing field using widely.In actual use, the disrepair phenomenon that ruptures appears in the edge of gray iron casting easily.But because the gray iron casting solderability is poor, the weld pool solidifies that welding produces is fast, and weld seam and nearly seam district very easily produce spoken parts in traditional operas and fragility martensitic structure, and hardness is very high, and extremely difficulty is carried out machining, thereby the Welding Repair of Cast Iron difficulty is increased; Low, the poor plasticity of gray iron casting intensity because of the local nonuniform heating of welding can produce bigger welding stress with cooling off fast, causes weld seam and heat affected area to crack simultaneously, and gray iron casting is scrapped.At present, never have the repair by welding problem that effective method solves the gray iron casting edge.

Summary of the invention

Technical problem to be solved by this invention provides a kind of gray iron casting edge welding casting repair technology; This technology can be eliminated the white cast-iron that gray iron casting edge weld forms; Improved gray iron casting repair welding zone machines processing characteristics, simple to operate, effect is obvious.

In order to solve the problems of the technologies described above, the present invention takes following technical scheme:

A kind of gray iron casting edge welding casting repair technology, it may further comprise the steps:

(a) electrode for cast iron with 5mm and above diameter was toasting between 150~200 ℃ 2~3 hours;

(b) use the sand papering breakage, remove gray iron casting breakage surface irregularities, utilize molding sand to make sand mold, make the sand mold interior shape identical with the new casting pig shape that will fill up in the gray iron casting breakage outside;

(c) 55~65 times electric current with core diameter melts electrode for cast iron in sand mold, removes the welding residue that produces simultaneously;

(d) constantly accumulate the molten iron that welding rod melts, to being full of whole sand mold; At this moment the temperature of molten iron can reach about 1150 ℃ in the sand mold;

(e) toast at sand mold placed around electrothermal furnace; The temperature of electrothermal furnace is controlled at 700~950 ℃; Make molten iron cools down in the sand mold solidify and form unified wholely with former gray iron casting, be incubated 2~3 hours, the power supply of closing electrothermal furnace no longer heats; When the gray iron casting temperature is reduced to 500~550 ℃, remove the electrothermal furnace air cooling to room temperature; Utilize casting pig in the above spoken parts in traditional operas high-temperature carbonization annealing of eutectoid temperature principle; During soak; Make high cementite of trip and eutectic cementite be decomposed into graphite and austenite; Because the decomposition of cementite, the white structure of having eliminated gray iron casting causes decrease of hardness, thereby has improved machinability;

(f) remove sand mold, mend is processed polishing.

Beneficial effect of the present invention is: the high heat that utilizes the large-current electric weldering to be produced, and need mend to melt simultaneously major diameter welding rod and ironcasting, cast repairing; And utilized the electrothermal furnace baking and thermal insulation 2~3 hours; Gray iron casting at high temperature is incubated, thereby makes high cementite of the trip that produces in the repair welding casting process and eutectic cementite be decomposed into graphite and austenite, because the decomposition of cementite; Gray iron casting white structure high-temperature carbonization annealing, thus machinability improved.This technology has provided concrete operations step and the technological parameter of repairing after the gray iron casting edge breakage disappearance; Welding casting by this step and parameter repairs; Can cast out at the damaged disappearance of gray iron casting place and the firm new casting pig that combines of one of former ironcasting, thus realization excellent repairing effect.The present invention is simple to operate, and is convenient.

The specific embodiment

Embodiment:

Gray iron casting in the daily production is more, like motor, and construction frock etc., the easy damaged threshing in edge of gray iron casting in the process of using, carrying stays incompleteness, thereby gray iron casting can not intactly be played a role.During repairing, selecting diameter is that the welding rod (Z248 type) of 5mm is in the random time of toasting the arbitrary temp between 150 ℃~200 ℃ under between 2~3 hours; Then gray iron casting is positioned on the construction table top; Use the sand papering breakage, remove gray iron casting breakage surface irregularities, utilize molding sand to make sand mold then in the gray iron casting breakage outside; Make the sand mold interior shape identical with the new casting pig shape that will fill up; Select any electric current between 275~325 amperes of the welding currents then, breakage is welded, a large amount of heat that electric welding produces melts welding rod and gray iron casting breakage; Welding rod produces molten iron and is deposited in the sand mold, clears up the welding residue of generation simultaneously rapidly with iron clamp; Constantly accumulate the molten iron of welding rod fusing, to being full of whole sand mold; At this moment the temperature of molten iron can reach about 1150 ℃ in the sand mold; Toast at sand mold placed around electrothermal furnace; The temperature of electrothermal furnace is controlled at arbitrary temp between 700~950 ℃; Make molten iron cools down in the sand mold solidify and with former gray iron casting form unified whole, be incubated 2~3 hours between random time, the power supply of closing electrothermal furnace no longer heats; When the gray iron casting temperature is reduced to 500~550 ℃ arbitrary temp, remove the electrothermal furnace air cooling to room temperature.New production casting iron block removes sand mold in the sand mold, and mend is processed polishing, removes burr.

The employed electrode for cast iron of present embodiment is 6mm, 7mm, 8mm, 9mm, 10mm or the like also, and its welding current is chosen arbitrarily according to 55~65 times of core diameter.

Some factors are to the influence of welding effect in the welding:

1, the influence of core diameter (chilling temperature, time same as the previously described embodiments)

Diameter/millimeter 2.5 3.2 4 5 6 ? 130~160 170~200 220~260 275~325 330~390 Welding effect Very easily produce white structure, crackle appears in the part part Be prone to produce white structure, crackle appears in the part part Be prone to produce white structure, crackle seldom occurs Produce a small amount of white structure, crackle do not occur Produce a small amount of white structure, crackle seldom occurs

2, the influence of welding current (core diameter and chilling temperature, time same as the previously described embodiments)

Electric current/ampere 170~200 220~260 275~325 330~390 450~550 Welding effect Be prone to produce white structure, crackle appears in the part part Be prone to produce white structure, crackle seldom occurs Do not produce white structure, crackle do not occur Be difficult for producing white structure, crackle seldom occurs Splash during welding, smog is big, and welding rod is rubescent,

3, the influence of holding temperature, the time is 120 minutes (core diameter is identical with embodiment with welding current)

Holding temperature/℃ 300~500 500~700 700~800 800~900 900~950 Welding effect Very easily produce white structure, crackle appears in the part part Be prone to produce white structure, crackle appears in the part part Produce micro-white structure, crackle seldom occurs Produce micro-white structure, crackle seldom occurs Produce micro-white structure, crackle seldom occurs

Annotate: (1) 300~500 expression is more than or equal to 300, and is less than 500, roughly the same surplus.

(2) in the welding effect, carbon is all with cementite (Fe in " white structure " 3C) tissue of carbide form existence, fracture becomes brilliant white, and is crisp and hard, is difficult to processed.

Claims (1)

1. repair technology is cast in a gray iron casting edge welding, and it is characterized in that: it may further comprise the steps:
(a) electrode for cast iron with 5mm and above diameter was toasting between 150~200 ℃ 2~3 hours;
(b) use the sand papering breakage, remove gray iron casting breakage surface irregularities, utilize molding sand to make sand mold, make the sand mold interior shape identical with the new casting pig shape that will fill up in the gray iron casting breakage outside;
(c) 55~65 times electric current with core diameter melts electrode for cast iron in sand mold, removes the welding residue that produces simultaneously;
(d) constantly accumulate the molten iron that welding rod melts, to being full of whole sand mold;
(e) toast at sand mold placed around electrothermal furnace; The temperature of electrothermal furnace is controlled at 700~950 ℃; Make molten iron cools down in the sand mold solidify and form unified wholely with former gray iron casting, be incubated 2~3 hours, the power supply of closing electrothermal furnace no longer heats; When the gray iron casting temperature is reduced to 500~550 ℃, remove the electrothermal furnace air cooling to room temperature;
(f) remove sand mold, mend is processed polishing.
CN201110421481XA 2011-12-16 2011-12-16 Edge welding casting repair process of grey iron casting CN102527999A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201110421481XA CN102527999A (en) 2011-12-16 2011-12-16 Edge welding casting repair process of grey iron casting

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201110421481XA CN102527999A (en) 2011-12-16 2011-12-16 Edge welding casting repair process of grey iron casting

Publications (1)

Publication Number Publication Date
CN102527999A true CN102527999A (en) 2012-07-04

Family

ID=46336716

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201110421481XA CN102527999A (en) 2011-12-16 2011-12-16 Edge welding casting repair process of grey iron casting

Country Status (1)

Country Link
CN (1) CN102527999A (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1278464A (en) * 2000-05-09 2001-01-03 赵朝顺 Casting-on method of inner and outer cast iron end cap of water turbine with white cast iron
CN1404944A (en) * 2001-08-17 2003-03-26 国成军 Composite casting technology
EP1396299A1 (en) * 2002-09-06 2004-03-10 Siemens Aktiengesellschaft Process for filling up a hole in a component
CN1819892A (en) * 2003-05-02 2006-08-16 卡特彼勒公司 Method for repairing a casting

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1278464A (en) * 2000-05-09 2001-01-03 赵朝顺 Casting-on method of inner and outer cast iron end cap of water turbine with white cast iron
CN1404944A (en) * 2001-08-17 2003-03-26 国成军 Composite casting technology
EP1396299A1 (en) * 2002-09-06 2004-03-10 Siemens Aktiengesellschaft Process for filling up a hole in a component
CN1819892A (en) * 2003-05-02 2006-08-16 卡特彼勒公司 Method for repairing a casting

Similar Documents

Publication Publication Date Title
CN101607311B (en) Fast forming method of fusion of metal powder of three beams of laser compound scanning
CN102350476B (en) Method for manufacturing large cake forgings of high-carbon and high-chromium cold working die steel
CN101343705B (en) Titanium alloy for high-rigidity cast and manufacturing method
CN102995001B (en) Method for restoring fatigue cracks of die through laser
CN101628374B (en) Method for preparing forging mould by double-layer metal resurfacing welding based on cast steel substrate
CN106244832A (en) Manufacturing process for high intensity alusil alloy round bar
CN105290703B (en) A kind of method that hot roll is worn with submerged arc overlay welding and laser melting coating reparation
CN102837165B (en) Manufacturing method for final-stage driving gear of high-power coal mining machine
CN101994512B (en) Technology for manufacturing cutting tooth for mining coal and minerals
CN103334061B (en) High thermal conductivity large section die-casting die steel and preparation thereof and heat treating method
JP2007332420A (en) Method for producing titanium material and stock for hot rolling
CN100537116C (en) Build-up welding process for low-alloy cast iron valve body sealing surface
CN101905184B (en) Liquid-state bimetal composite hammer for crusher and manufacturing method thereof
KR100582802B1 (en) Method of preparing a magnesium alloy slab for hot-rolling and method of hot-rolling magnesium alloy
WO2002052051A2 (en) Methods of melting titanium and other metals and alloys by plasma arc or electron beam
CN104164574B (en) A kind of electroslag remelting prepares the method for high-rating generator retaining ring hollow steel ingot
CN104526167A (en) Electric smelting forming method of hydrogenation reactor barrel
CN102312172B (en) B3R hot work die steel with high strength and toughness and resistance to tempering, and preparation process thereof
CN105102679A (en) Titanium slab for hot rolling and method for manufacturing same
CN102974742B (en) Processing method of movable fork
CN103333997B (en) Annealing heat treatment method of H13 die steel
CN104259438A (en) Copper-steel bimetal casting improved technology
CN101342626B (en) Welding method and silver based metal for hard-alloy heavy type cutting tools
US20050173496A1 (en) Method of build up welding to thin-walled portion
CN103706740B (en) A kind of forging method of annular GH105 high temperature alloy forging

Legal Events

Date Code Title Description
PB01 Publication
C06 Publication
SE01 Entry into force of request for substantive examination
C10 Entry into substantive examination
AD01 Patent right deemed abandoned

Effective date of abandoning: 20120704

C20 Patent right or utility model deemed to be abandoned or is abandoned