CN1086965C - Technology for manufacturing mandrel used to roll seamless steel tube - Google Patents
Technology for manufacturing mandrel used to roll seamless steel tube Download PDFInfo
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- CN1086965C CN1086965C CN99121827A CN99121827A CN1086965C CN 1086965 C CN1086965 C CN 1086965C CN 99121827 A CN99121827 A CN 99121827A CN 99121827 A CN99121827 A CN 99121827A CN 1086965 C CN1086965 C CN 1086965C
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Abstract
The present invention relates to a new technical skill of the production of core rods for rolling seamless steel pipes, which belongs to the technology of processing workpieces. The present invention comprises the steps of material selection, refinement, cogging forging operation, precision forging formation, anneal processing, thermal refining treatment and inspection. The present invention bridges a gap in domestic technical skills of the production of core rods for seamless steel pipes, a large amount of foreign exchange is saved for China, and a wide prospect is provided for the production of core rods for seamless steel pipes in China.
Description
The present invention relates to the novel technique that a kind of used to roll seamless steel tube plug is produced, belong to the workpiece process technology.
At present, along with the fast development of Chinese national economy, the output of steel of China has leapt to the No. 1 in the world, yet, the required plug of China's seamless steel tube production dependence on import always so far, the plug production technology still is a blank in China.China will expend the plug of a large amount of foreign exchanges from the countries concerned's import used to roll seamless steel tube every year, the production that is restricting China's seamless steel pipe that it is serious, this is extremely unbecoming with our such output of steel big country, so it is imperative to develop the novel technique of used to roll seamless steel tube plug production.
The novel technique that the object of the present invention is to provide a kind of used to roll seamless steel tube plug to produce is to fill up the blank of China.
The object of the present invention is achieved like this: it through select materials, refining, cogging forging, precision forging, annealing processing, modified heat treatment, check form, it is characterized in that: it is by following technology preparation:
One, selects materials
Select the 4Cr5MoSiV1 electric arc furnaces steel ingot among the GB1299-85 for use,
Two, the refining of steel
Two kinds of methods are arranged: the outer vacuum protection refining steel ingot of electroslag remelting refining steel ingot or stove,
Electroslag remelting refining steel ingot:
1. adopt CaF
2, Al
2O
3The binary slag system, slag charge will fully be dried, and is not with crystallization moisture content,
2. the electroslag remelting melting rate is controlled at≤600Kg/ hour, and inaccurate the interpolation is intended to any additional source material of alloying in the reflow process,
3. the ingot mould cool time must not surpass 1 hour, wants slow cooling after the demoulding, and the slow cooling time must not be less than 48 hours, temperature behind the ingot slow cool must not be higher than 150 ℃, but can not the demoulding too early, is as the criterion with molten steel solidification, will in time anneal behind the ingot slow cool, 4. the steel ingot weight after the refining should be about 8 tons
Steel ingot section 〉=Φ 720mm or 700mm * 700mm; the outer vacuum protection refining steel ingot of stove: adopt electric arc furnaces-external refining duplex practice; 1. melt in the electric arc furnaces; 2. the outer alloying of stove; degassing refining; 3. will guarantee enough vacuum conditions and gas protective condition, 4. the steel ingot weight after the refining should be about 8 tons
Steel ingot section 〉=Φ 720mm or 〉=700mm * 700mm, 5. steel ingot will in time be annealed, three, the cogging of steel ingot is forged and is 1. adopted oil pressure to forge machine cogging or employing open die forging or dydraulic forging cogging soon, 2. intermediate blank be of a size of Φ 450-500mm * 3.5-4.0m 3. heating-up temperature be 1200 ℃, ℃ 4. opening and forging temperature is 1150-1180 ℃, and final forging temperature 〉=900 are the slow cooling forging stock, check and the reconditioning blemish, 5. diffusion annealing is carried out in the car-type chamber furnace
Annealing temperature 680-750 ℃, constant temperature time 〉=10 hour,
Programming rate is controlled to be ≯ and 80 ℃/hour, cooling rate ≯ 50 ℃/hour, four, 1. precision forging adopts precise forging machine one fire to forge to become a useful person or adopt the many fire of fast forging machine to forge, 2. the appearance and size of finished product plug is: Φ 240mm * 15300mm
Tolerance is: Φ 240mm ± 2mm
Length is: 15300mm+50mm
15300mm-0mm
Flexibility is: length overall flexibility≤6mm
Ovality is: the section tolerance 70% 3. heating-up temperature be 1200 ℃, opening and forging temperature is 1150-1180 ℃, ℃ 4. should pack into immediately behind the forging and molding and carry out diffusion annealing in the annealing furnace in final forging temperature 〉=900,
Five, annealing processing
1. adopt superhuge car-type bell furnace,
2. 880-900 ℃ of long-time constant temperature, air cooling to 350 ℃,
3. 750-780 ℃ of long-time constant temperature, stove is chilled to below 200 ℃ and comes out of the stove,
4. ultrasonic examination initial survey, and localized resection end to end, the finished product cut lengths is 15.3m,
Length tolerance is+50mm,
5. 500-1000 ton oil pressure straightener is aligned plug, and the length overall perpendicularity is no more than 8mm,
6. adopt length to cut peeling roughing greater than 16 meters overlength lathe,
Its section tolerance is: Φ 240mm ± 2mm, total flexibility≤6mm
The Surface Machining precision is: 3- 4
7. forging product inspection
Six, modified heat treatment
(1) heat treatment of finished product plug has two kinds of heat treatment methods: surperficial Fast Heating heat treatment or integral body heat hot are at a slow speed handled,
Surface Fast Heating heat treatment
1. adopt rollaway type line-frequency induction heater to carry out,
2. quench,
Preheating for the first time: 400 ℃ of temperature, plug translational speed≤150mm/ branch, air cooling,
Preheating for the second time: 700 ℃ of temperature, plug translational speed≤150mm/ branch, air cooling,
Quench: temperature 980-1020 ℃, plug translational speed 130mm/ branch, air cooling or blowing cooling or atomized water blowing cooling,
3. tempering,
Tempering: temperature 680-720 ℃ for the first time, plug translational speed 100mm/ branch, air cooling,
Tempering: temperature 550-620 ℃ for the second time, plug translational speed 100mm/ branch, air cooling,
Or integral body heat hot processing at a slow speed
1. adopt ultradeep well formula or overlength chassis Scale Bell-type Heat Treatment Furnace to carry out,
2. quench,
Temperature 980-1020 ℃,
Firing rate≤80 ℃/hour, air cooling or oil cooling,
3. tempering,
Tempering: temperature 680-720 ℃ for the first time, firing rate≤80 ℃/hour, air cooling or oil cooling,
Tempering: temperature 550-620 ℃ for the second time, firing rate≤80 ℃/hour, air cooling or oil cooling,
(2), after the finished product heat treatment if distortion is serious, must align again,
Plug is heated to 500 ℃ at a slow speed, and the band temperature correction is straight
Stress relief annealing, annealing temperature 200-300 ℃, time＞16 hour,
Seven, product inspection
1. ultrasonic examination check
2. case hardness test
3. chemical composition analysis is carried out in sampling
4. macrostructure quality examination
5. the inspection of metallographic field trash
6. the detection of mechanical property
7. appearance and size inspection
8. surface quality inspection
9. packing promptly gets used to roll seamless steel tube plug product of the present invention.
Its feature also is described steel grade, and it is the steel ingot that is gone out greater than 8 tons electric arc furnace smelting by capacity, its optimization of Chemical Composition following (%):
C 0.33-0.37 Si 0.80-1.10 Mn?0.40-0.50 Cr 4.60-5.40
MO?1.10-1.40 V 0.90-1.10 S ≤0.008 P+S?≤0.020
Residual aluminium content is 0.02-0.04% in the steel
Appearance and size is:
Φ 400-450mm * 2-3m or (380-420mm)
2* 2-3m.
The present invention compared with prior art utilizes it can produce the plug of used to roll seamless steel tube.
Further specify the present invention below in conjunction with embodiment:
Embodiment:
One, selects materials
Select the 4Cr5MoSiV1 steel grade among the GB1 299-85 for use, it is the steel ingot that is gone out greater than 8 tons electric arc furnace smelting by capacity, and its chemical composition is (%):
C 0.35 Si 1.00 Mn 0.45 Cr 5.00
MO?1.20 V 1.00 S 0.005 P+S?0.013
Its appearance and size is:
Φ430mm×2.5m
Residual aluminium content is 0.03% in the steel.
Two, the refining of steel
Select electroslag remelting refining steel ingot for use:
1. adopt CaF
2, Al
2O
3Binary slag system proportioning is 70%: 30%, and slag charge will fully be dried, and is not with crystallization moisture content,
2. the electroslag remelting melting rate was controlled at 580-600Kg/ hour, did not add any additional source material in the reflow process,
3. the ingot mould cool time is 1 hour, slow cooling after the demoulding, and the slow cooling time is 48 hours, the temperature behind the ingot slow cool is 150 ℃, annealing immediately after the slow cooling,
4. the steel ingot weight after the refining is 8 tons,
The steel ingot section is Φ 750mm,
Three, the cogging of steel ingot is forged
1. adopt oil pressure to forge the machine cogging soon,
2. intermediate blank is of a size of Φ 480mm * 3.8m
3. heating-up temperature is 1200 ℃, and opening and forging temperature is 1160 ℃, 900 ℃ of final forging temperatures
4. the slow cooling forging stock is checked and the reconditioning blemish,
5. diffusion annealing is carried out in the car-type chamber furnace,
700 ℃ of annealing temperatures, constant temperature time 12 hours,
Programming rate is controlled to be 60 ℃/hour, 40 ℃/hour of cooling rates,
Four, 1. precision forging adopts precise forging machine one fire forging to become a useful person, and the appearance and size of 2. forging plug is: Φ 250mm
Tolerance is: Φ 250mm+2mm
Ovality is: 2mm
Length is: 18m 3. heating-up temperature is 1200 ℃, opening and forging temperature is 1160 ℃, 4. 950 ℃ of final forging temperatures are packed into immediately behind the forging and molding and are carried out diffusion annealing in the annealing furnace, five, 1. annealing processing adopt superhuge car-type bell furnace, 2. 880-900 ℃ of long-time constant temperature, air cooling to 350 ℃, 3. 750-780 ℃ of long-time constant temperature, stove is chilled to below 200 ℃ and comes out of the stove, 4. the ultrasonic examination initial survey, and localized resection end to end after, length is 15.35m, 5. adopts 1000 tons of oil pressure straightener aligning plugs, and the length overall perpendicularity is no more than 6mm, 6. adopt length to cut peeling roughing greater than 16 meters overlength lathe
Its size and section tolerance are: Φ 240mm+1mm
Surface accuracy is: 7. product inspection six of 3- 4, modified heat treatment (1), selects for use surperficial Fast Heating heat treatment 1. to adopt rollaway type line-frequency induction heater to carry out, 2. quenches,
Preheating for the first time: 400 ℃ of temperature, plug translational speed are the 150mm/ branch, air cooling,
Preheating for the second time: 700 ℃ of temperature, plug translational speed are the 150mm/ branch, air cooling,
Quench: 1000 ℃ of temperature, plug translational speed 130mm/ branch, air cooling, 3. tempering,
Tempering for the first time: 700 ℃ of temperature, plug translational speed 100mm/ branch, air cooling,
Tempering for the second time: 580 ℃ of temperature, plug translational speed 100mm/ branch, air cooling,
(2) align again after the finished product heat treatment,
Plug is heated to 500 ℃ at a slow speed, and the band temperature correction is straight
Stress relief annealing, 250 ℃ of annealing temperatures, the time is 20 hours,
Seven, product inspection
1. ultrasonic examination check
2. case hardness test
3. chemical composition analysis is carried out in sampling
4. macrostructure quality examination
5. the inspection of metallographic field trash
6. the detection of mechanical property
7. appearance and size inspection
8. surface quality inspection
9. packing promptly gets used to roll seamless steel tube plug product of the present invention.
Adopt the novel technique of used to roll seamless steel tube plug of the present invention production to manufacture experimently into three plug samples, it is on probation to meet in the relevant company machine, result on trial shows: properties of product are good, satisfied the needs of used to roll seamless steel tube, filled up the blank of China.
Claims (2)
1, the novel technique produced of a kind of used to roll seamless steel tube plug, it through select materials, refining, cogging forging, precision forging, annealing processing, modified heat treatment, check form, it is characterized in that: it is to prepare by following technology:
One, selects materials
Select the 4Cr5MoSiV1 electric arc furnaces steel ingot among the GB1299-85 for use,
Two, the refining of steel
Two kinds of methods are arranged: the outer vacuum protection refining steel ingot of electroslag remelting refining steel ingot or stove,
Electroslag remelting refining steel ingot:
1. adopt CaF
2, Al
2O
3The binary slag system, slag charge will fully be dried, and is not with crystallization moisture content,
2. the electroslag remelting melting rate is controlled at≤600Kg/ hour, and inaccurate the interpolation is intended to any additional source material of alloying in the reflow process,
3. the ingot mould cool time must not surpass 1 hour, want slow cooling after the demoulding, and the slow cooling time must not be less than 48 hours, and the temperature behind the ingot slow cool must not be higher than 150 ℃, but can not the demoulding too early, is as the criterion with molten steel solidification, in time anneal behind the ingot slow cool,
4. the steel ingot weight after the refining should be about 8 tons,
Steel ingot section 〉=Φ 720mm or 〉=700mm * 700mm,
The outer vacuum protection refining steel ingot of stove: adopt electric arc furnaces-external refining duplex practice,
1. melt in the electric arc furnaces,
2. the outer alloying of stove, degassing refining,
3. to guarantee enough vacuum conditions and gas protective condition,
4. the steel ingot weight after the refining should be about 8 tons,
Steel ingot section 〉=Φ 720mm or 〉=700mm * 700mm,
5. steel ingot will in time be annealed, three, the cogging of steel ingot is forged and is 1. adopted oil pressure to forge machine cogging or employing open die forging or dydraulic forging cogging soon, 2. intermediate blank be of a size of Φ 450-500mm * 3.5-4.0m 3. heating-up temperature be 1200 ℃, opening and forging temperature is 1150-1180 ℃, ℃ 4. final forging temperature 〉=900 are the slow cooling forging stock, check and the reconditioning blemish that 5. diffusion annealing is carried out in the car-type chamber furnace
Annealing temperature 680-750 ℃, constant temperature time 〉=10 hour,
Programming rate is controlled to be ≯ and 80 ℃/hour, cooling rate ≯ 50 ℃/hour, four, 1. precision forging adopts precise forging machine one fire to forge to become a useful person or adopt the many fire of fast forging machine to forge, 2. the appearance and size of finished product plug is: Φ 240mm * 15300mm
Tolerance is: Φ 240mm ± 2mm
Length is: 15300mm+50mm
15300mm-0mm
Flexibility is: length overall flexibility≤6mm
Ovality is: the section tolerance 70% 3. heating-up temperature be 1200 ℃, opening and forging temperature is 1150-1180 ℃, ℃ 4. should pack into immediately behind the forging and molding and carry out diffusion annealing in the annealing furnace in final forging temperature 〉=900, five, 1. annealing processing adopt superhuge car-type bell furnace, 2. 880-900 ℃ of long-time constant temperature, air cooling to 350 ℃, 3. 750-780 ℃ of long-time constant temperature, stove is chilled to below 200 ℃ and comes out of the stove, 4. ultrasonic examination initial survey, and localized resection end to end, and the finished product cut lengths is 15.3m
Length tolerance is+50mm, 5. 500-1000 ton oil pressure straightener aligning plug, and the length overall perpendicularity is no more than 8mm, 6. adopts length to cut peeling roughing greater than 16 meters overlength lathe,
Its section tolerance is: Φ 240mm ± 2mm
The Surface Machining precision is: 3- 4 7. forging product inspections
Six, modified heat treatment
(1) heat treatment of finished product plug has two kinds of heat treatment methods: surperficial Fast Heating heat treatment or integral body heat hot are at a slow speed handled,
Surface Fast Heating heat treatment
1. adopt rollaway type line-frequency induction heater to carry out,
2. quench,
Preheating for the first time: 400 ℃ of temperature, plug translational speed≤150mm/ branch, air cooling,
Preheating for the second time: 700 ℃ of temperature, plug translational speed≤150mm/ branch, air cooling,
Quench: temperature 980-1020 ℃, plug translational speed 130mm/ branch, air cooling or blowing cooling or atomized water blowing cooling,
3. tempering,
Tempering: temperature 680-720 ℃ for the first time, plug translational speed 100mm/ branch, air cooling,
Tempering: temperature 550-620 ℃ for the second time, plug translational speed 100mm/ branch, air cooling,
Or integral body heat hot processing at a slow speed
1. adopt ultradeep well formula or overlength chassis Scale Bell-type Heat Treatment Furnace to carry out,
2. quench,
Temperature 980-1020 ℃,
Firing rate≤80 ℃/hour, air cooling or oil cooling,
3. tempering,
Tempering: temperature 680-720 ℃ for the first time, firing rate≤80 ℃/hour, air cooling or oil cooling,
Tempering: temperature 550-620 ℃ for the second time, firing rate≤80 ℃/hour, air cooling or oil cooling,
(2) serious after the finished product heat treatment as if distortion, must align again,
Plug is heated to 500 ℃ at a slow speed, and the band temperature correction is straight
Stress relief annealing, annealing temperature 200-300 ℃, time＞16 hour,
Seven, product inspection
1. ultrasonic examination check
2. case hardness test
3. chemical composition analysis is carried out in sampling
4. macrostructure quality examination
5. the inspection of metallographic field trash
6. the detection of mechanical property
7. appearance and size inspection
8. surface quality inspection
9. packing promptly gets used to roll seamless steel tube plug product of the present invention.
2, the novel technique produced of used to roll seamless steel tube plug according to claim 1, its feature also is described steel grade, and it is the steel ingot that is gone out greater than 8 tons electric arc furnace smelting by capacity, and it contains optimization of Chemical Composition following (%):
C?0.33-0.37 Si 0.80-1.10 Mn?0.40-0.50 Cr 4.60-5.40
MO?1.10-1.40?V 0.90-1.10 S ≤0.008 P+S?≤0.020
Residual aluminium content is in the steel: 0.02-0.04%
Its appearance and size is:
Φ 400-450mm * 2-3m or (380-420mm)
2* 2-3m.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN99121827A CN1086965C (en) | 1999-10-19 | 1999-10-19 | Technology for manufacturing mandrel used to roll seamless steel tube |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN99121827A CN1086965C (en) | 1999-10-19 | 1999-10-19 | Technology for manufacturing mandrel used to roll seamless steel tube |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1251786A CN1251786A (en) | 2000-05-03 |
| CN1086965C true CN1086965C (en) | 2002-07-03 |
Family
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN99121827A Ceased CN1086965C (en) | 1999-10-19 | 1999-10-19 | Technology for manufacturing mandrel used to roll seamless steel tube |
Country Status (1)
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| CN (1) | CN1086965C (en) |
Cited By (1)
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| CN100430181C (en) * | 2005-03-30 | 2008-11-05 | 宝山钢铁股份有限公司 | Novel process for manufacturing retained mandrel for continuous rolling of steel pipe |
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Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1230138A (en) * | 1996-12-27 | 1999-09-29 | 川崎制铁株式会社 | Plug and mandrel bar for rolling of seamless steel pipe and method of mfg. seamless steel pipe |
-
1999
- 1999-10-19 CN CN99121827A patent/CN1086965C/en not_active Ceased
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1230138A (en) * | 1996-12-27 | 1999-09-29 | 川崎制铁株式会社 | Plug and mandrel bar for rolling of seamless steel pipe and method of mfg. seamless steel pipe |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100430181C (en) * | 2005-03-30 | 2008-11-05 | 宝山钢铁股份有限公司 | Novel process for manufacturing retained mandrel for continuous rolling of steel pipe |
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| Publication number | Publication date |
|---|---|
| CN1251786A (en) | 2000-05-03 |
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