CN105132790A - Vanadium-containing carbidic austempered ductile iron and preparation method thereof - Google Patents
Vanadium-containing carbidic austempered ductile iron and preparation method thereof Download PDFInfo
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- CN105132790A CN105132790A CN201510546312.7A CN201510546312A CN105132790A CN 105132790 A CN105132790 A CN 105132790A CN 201510546312 A CN201510546312 A CN 201510546312A CN 105132790 A CN105132790 A CN 105132790A
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Abstract
A vanadium-containing carbidic austempered ductile iron comprises the following ingredients in percent by mass: 3.20-3.70 percent of C, 2.50-3.30 percent of Si, 0.4-0.8 percent of Mn, less than or equal to 0.040 percent of P, less than or equal to 0.007 percent of S, 0.01-0.04 percent of Ce, 0.01-0.04 percent of Mg, 0.30-1.80 percent of Cr, 0.25-0.70 percent of V and the balance of Fe. The preparation method of the vanadium-containing carbidic austempered ductile iron comprises the following steps: (1), heating and smelting pig iron, steel scrap, ferromanganese and ferrovanadium; (2), placing a rare-earth magnesium nodularizer into a groove in the bottom of a ladle, placing a nucleating agent on the rare-earth magnesium nodularizer, casting for 10-30 s at the temperature of 1,350-1,430 DEG C, and cooling to obtain ductile iron; and (3), heating the cooled ductile iron to reach a temperature of 850-920 DEG C, keeping the temperature for 2-4 h, then placing the heated ductile iron into 45% KNO3+55% NaNO3 molten salt at the temperature of 280-320 DEG C, keeping the temperature for 1-3 h, taking out the ductile iron, and cooling the ductile iron to the ordinary temperature to obtain the vanadium-containing carbidic austempered ductile iron. The vanadium-containing carbidic austempered ductile iron is high in ductility and hardness and excellent in comprehensive mechanical property.
Description
Technical field
The present invention relates to a kind of spheroidal graphite cast iron and preparation method thereof, specifically relate to a kind of containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron and preparation method thereof, belong to metallurgical casting field.
Background technology
At present, the high-abrasive material applied in the industries such as metallurgy, mine is of a great variety, but can lose efficacy rapidly due to wearing and tearing at many workpiece of these industries and equipment.Although fret wear seldom causes the catastrophic harm of metal works, its financial loss caused also is surprising, annual because the loss caused of wearing and tearing just reaches more than 1,000 hundred million in China according to statistics.In today that global resources are day by day exhausted, this is a huge consumption, white cast iron and high mangaenese steel, ni-hard cast iron, the different high-abrasive material such as high-chromium white cast iron serves very large effect in different developmental stage to the consumption of reduction unit materials, but there is different problems in these materials in performance, as lower in ordinary white cast iron toughness, high mangaenese steel work hardening capacity under low shock load is poor, rich chromium cast iron makes perishable inefficacy because of corrosion under the wet-milling condition of corrosive medium, and toughness is also inadequate simultaneously.Therefore, impel people from other approach Development of New Generation New Kind of Anti-Abrasion material, the spurt in prices of various iron alloy, causes high-abrasive material manufacturing cost to rise simultaneously.A kind of New Kind of Anti-Abrasion material that carbide-containing ausferrite spheroidal graphite cast iron (CADI) grows up just in such a situa-tion, has high comprehensive performance, feature with low cost.
The austempering ductile iron (CADI) of carbide-containing is as the derived material of ADI, first within 1992, developed by the U.S., add the alloying element that some easily form carbide, thus generate a certain amount of carbide, research shows CADI distinctive bainite+residual austenite matrix, while enabling CADI material obtain wear resistance, there is higher impact toughness, more cheap than white cast iron, high mangaenese steel in cost.Therefore be applied to and toughness and hardness be there are certain requirements, and the part of relative wear resistance, CADI is best selection.
CN103320647A discloses a kind of band carbide austempored ductile iron and quenching technology thereof, and the chemical composition of this cast iron and massfraction are C:3.3 ~ 3.8%; P:0.01 ~ 0.05%; S:0.005 ~ 0.02%; Mg:0.025 ~ 0.045%; Re:0.015 ~ 0.03%; Sn:0.1 ~ 0.8%; Si:2.8 ~ 3.6%; Mn:1.5 ~ 2.8%; Cr:0.2 ~ 0.8%; B:0.02 ~ 0.08%; Surplus is iron.After thermal treatment, tensile strength reaches δ b>=700MPa, and impelling strength is 8 ~ 15J/cm
2but hardness is that 56 ~ 62HRC result improves that hardness hardness is too high is unfavorable for machining, and this thermal treatment process is twin-stage quenching expends time in many and waste resource is unfavorable for suitability for industrialized production.
CN101589661A discloses a kind of with carbide austempored ductile iron ploughshare and production method, and the chemical composition of this cast iron and massfraction are C:3.40 ~ 3.80; Si:2.20 ~ 2.80; Mn:0.20 ~ 0.50; P≤0.030; S≤0.002; Mg:0.03 ~ 0.04; Cr:0.25 ~ 0.50; Re:0.01 ~ 0.02; Surplus is iron.The hardness that this magnesium iron finally reaches is the wear resistance that 58HRC improves product, but the tempering stage that this thermal treatment process is last, causes thermal treatment process complicated, be unfavorable for industrial production.This material only relates to making ploughshare, and range of application is narrow, and its use is subject to a definite limitation.
Summary of the invention
The hardness that the object of the invention is to overcome prior art is high and toughness is low, easy fracture, range of application are narrower defect, propose a kind of comprehensive mechanical property good containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron.
Another object of the present invention proposes a kind of described simple to operate containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron, can the preparation method of industrialized mass production.
Composition containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron of the present invention and mass percentage: C:3.20 ~ 3.70; Si:2.50 ~ 3.30; Mn:0.4 ~ 0.8; P≤0.040; S≤0.007; Ce:0.01 ~ 0.04; Mg:0.01 ~ 0.04; Cr:0.30 ~ 1.80; V:0.25 ~ 0.70; Surplus is iron.
The present invention is preferably containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron composition and mass percentage: C:3.23 ~ 3.60; Si:2.69 ~ 3.01; Mn:0.50 ~ 1.00; P≤0.040; S≤0.008; Ce:0.01 ~ 0.04; Mg:0.012 ~ 0.030; Cr:0.30 ~ 1.50; V:0.19 ~ 0.68; Surplus is iron.
Forming and mass percentage: C:3.37 containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron of the best of the present invention; Si:2.79; Mn:00.58; P:0.038; S:0.006; Ce:0.019; Mg:0.012; Cr:1.15; V:0.68; Surplus is iron.
The present invention adds the elemental vanadium of appropriate formation carbide, for the formation of the carbide of different shapes and size, is uniformly distributed in preferably in matrix, suppresses or avoid the formation of carbide network, prevents from isolating effect to matrix, thus reduces the toughness of material.
Suitable Mn and Si constituent content, mainly contains the mixed type spheroidal graphite cast iron original structure helping be formed ferrite and pearlite in castingprocesses.Test shows: appropriate Mn element contributes to the hardening capacity improving material.
Preparation method containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron of the present invention, its concrete steps are:
(1) melting: the pig iron, steel scrap, ferromanganese and vanadium iron are added hot smelting, treats that iron liquid is heated to 1450 ~ 1520 DEG C and comes out of the stove;
(2) iron liquid spheroidization and inoculation process: adopt in bag and pour method spheroidization and inoculation, is placed in bag end groove, places VI-70RE nucleating agent above by VNCR-80 rare earth magnesium nodularizer; Before cast, put into cerium oxide in die cavity, teeming temperature 1350 ~ 1430 DEG C, 10 ~ 30 seconds durations of pouring, adopt sand mold dark chill Quick pouring die cavity, after cooling, obtain spheroidal graphite cast iron;
(3) salt bath austempering thermal treatment: by cooled spheroidal graphite cast iron, is heated to 850 ~ 920 DEG C, is incubated 2 ~ 4 hours, then puts into the 45%KN0 being heated to 280 ~ 320 DEG C
3+ 55%NaN0
3in fused salt, be incubated 1 ~ 3 hour, taking-up is placed in air and is cooled to normal temperature, obtains of the present invention containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron.
VNCR-80 rare earth magnesium nodularizer add-on is 1.0 ~ 2.0% of raw materials quality.
VI-70RE innoculant adding quantity is 0.5 ~ 1.0% of raw materials quality.
Cerium oxide add-on is 0.03% of raw materials quality.
The metallographic structure containing vanadium carbide iron difficult to understand body spheroidal graphite cast iron prepared of the inventive method is by the carbide of iron body difficult to understand, vanadium and graphite pebbles and paralympicly form.
The advantage of the present invention compared with existing carbide-containing ausferrite spheroidal graphite cast iron and preparation method thereof is:
1. the present invention adds V element on the formulated component of existing carbide-containing spheroidal graphite cast iron, make as cast condition formed when crystallization the higher bulk of hardness ratio containing vanadium carbide, be distributed in preferably in matrix, can suppress and avoid the formation of carbide network better.
2. the inventive method utilizes salt bath austempering thermal treatment process to obtain iron body difficult to understand (or being called bainite+residual austenite) matrix, and its tissue distribution is even, is conducive to the comprehensive mechanical property improving spheroidal graphite cast iron.
Accompanying drawing explanation
Fig. 1 embodiment 1 containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron electronic probe photo.
Fig. 2 embodiment 1 containing vanadium carbide iron body difficult to understand Spheroidal Graphite Cast Iron Metallographic Structure photo.
Fig. 3 embodiment 2 containing vanadium carbide iron body difficult to understand Spheroidal Graphite Cast Iron Metallographic Structure photo.
Fig. 4 embodiment 3 containing vanadium carbide iron body difficult to understand Spheroidal Graphite Cast Iron Metallographic Structure photo.
In figure: 1. carbide; 2. iron body difficult to understand; 3. graphite pebbles.
Embodiment
Embodiment 1
Composition and mass percent: C:3.23; Si:3.01; Mn:0.56; P:0.037; S:0.006; Ce:0.035; Mg:0.023; Cr:1.15; V:0.28; Surplus is iron.
(1) melting: the alloy furnace charges such as the pig iron configured, steel scrap, ferromanganese, vanadium iron are put into medium-frequency induction furnace, heats and be fused into nodular cast iron alloy iron liquid, stokehold testing and debugging composition, tapping temperature about 1510 DEG C.
(2) iron liquid spheroidization and inoculation process: adopt in bag and pour method spheroidization and inoculation, is placed in bag end groove, places the VI-70RE nucleating agent of raw materials quality 0.8% above by the VNCR-80 rare earth magnesium nodularizer of raw materials quality 1.8%; Before cast, put into the cerium oxide of raw materials quality 0.03% in die cavity, then pour into a mould alloy iron liquid, teeming temperature 1416 DEG C, 24 seconds durations of pouring, namely obtains spheroidal graphite cast iron after cooling.
(3) salt bath austempering thermal treatment: by above-mentioned spheroidal graphite cast iron, is heated to 900 DEG C, is incubated 2 hours, then puts into the 45%KN0 being heated to 310 DEG C
3+ 55%NaN0
3in fused salt, be incubated 2 hours, taking-up is placed in air and is cooled to normal temperature, obtains of the present invention containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron.Performance is in table 1.
Embodiment 2
Composition and mass percent: C:3.35; Si:2.81; Mn:0.57; P:0.038; S:0.006; Ce:0.023; Mg:0.013; Cr:1.15; V:0.50; Surplus is iron.
(1) melting: with embodiment 1.Tapping temperature 1530 DEG C.
(2) iron liquid spheroidization and inoculation process: with embodiment 1.Teeming temperature is 1425 DEG C, and the duration of pouring is 18 seconds, namely obtains spheroidal graphite cast iron after cooling.
(3) salt bath austempering thermal treatment: with embodiment 1.Performance is in table 1.
Embodiment 3
Composition and mass percent: C:3.37; Si:2.79; Mn:0.58; P:0.038; S:0.006; Ce:0.019; Mg:0.012; Cr:1.15; V:0.68; Surplus is iron.
(1) melting: with embodiment 1.Tapping temperature 1525 DEG C.
(2) iron liquid spheroidization and inoculation process: with embodiment 1.Teeming temperature is 1425 DEG C, and the duration of pouring is 18 seconds, namely obtains spheroidal graphite cast iron after cooling.
(3) salt bath austempering thermal treatment: with embodiment 1.Performance is in table 1.
Table 1 is of the present invention containing vanadium carbide iron body difficult to understand Alloy Affecting Ductile Properties
Note: Wear Test Data is tested under same operating mode, 1 kilogram of pressure, 30 minutes time.
(mass loss rate M=△ m/s.t).
Claims (7)
1., containing a vanadium carbide iron body difficult to understand spheroidal graphite cast iron, it is characterized in that composition and mass percentage: C:3.20 ~ 3.70; Si:2.50 ~ 3.30; Mn:0.4 ~ 0.8; P≤0.040; S≤0.007; Ce:0.01 ~ 0.04; Mg:0.01 ~ 0.04; Cr:0.30 ~ 1.80; V:0.25 ~ 0.70; Surplus is iron.
2. according to claim 1 containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron, it is characterized in that composition and mass percentage: C:3.23 ~ 3.60; Si:2.69 ~ 3.01; Mn:0.50 ~ 1.00; P≤0.040; S≤0.008; Ce:0.01 ~ 0.04; Mg:0.012 ~ 0.030; Cr:0.30 ~ 1.50; V:0.19 ~ 0.68; Surplus is iron.
3. according to claim 1 containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron, it is characterized in that composition and mass percentage: C:3.37; Si:2.79; Mn:00.58; P:0.038; S:0.006; Ce:0.019; Mg:0.012; Cr:1.15; V:0.68; Surplus is iron.
4. the preparation method containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron according to claim 1, is characterized in that being made up of following steps:
(1) melting: the pig iron, steel scrap, ferromanganese and vanadium iron are added hot smelting, treats that iron liquid is heated to 1450 ~ 1520 DEG C and comes out of the stove;
(2) iron liquid spheroidization and inoculation process: adopt in bag and pour method spheroidization and inoculation, is placed in bag end groove, places VI-70RE nucleating agent above by VNCR-80 rare earth magnesium nodularizer; Before cast, put into cerium oxide in die cavity, teeming temperature 1350 ~ 1430 DEG C, 10 ~ 30 seconds durations of pouring, adopt sand mold dark chill Quick pouring die cavity, after cooling, obtain spheroidal graphite cast iron;
(3) salt bath austempering thermal treatment: by cooled spheroidal graphite cast iron, is heated to 850 ~ 920 DEG C, is incubated 2 ~ 4 hours, then puts into the 45%KN0 being heated to 280 ~ 320 DEG C
3+ 55%NaN0
3in fused salt, be incubated 1 ~ 3 hour, taking-up is placed in air and is cooled to normal temperature, obtains of the present invention containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron.
5. the preparation method containing vanadium carbide iron body difficult to understand spheroidal graphite cast iron according to claim 4, is characterized in that described VNCR-80 rare earth magnesium nodularizer add-on is 1.0 ~ 2.0% of raw materials quality.
6. the preparation method of carbide-containing ausferrite spheroidal graphite cast iron according to claim 4, is characterized in that described VI-70RE innoculant adding quantity is 0.5 ~ 1.0% of raw materials quality.
7. the preparation method of carbide-containing ausferrite spheroidal graphite cast iron according to claim 4, is characterized in that described cerium oxide add-on is 0.03% of raw materials quality.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106319338A (en) * | 2016-08-31 | 2017-01-11 | 陕西同心连铸管业科技有限公司 | Self-lubricating rolling bearing and preparing method thereof |
| CN106834902A (en) * | 2017-03-14 | 2017-06-13 | 姜廷敏 | A kind of high-wearing feature carbide-containing ausferrite spheroidal graphite cast iron and preparation method thereof |
| CN115216585A (en) * | 2022-07-29 | 2022-10-21 | 宁国市华丰耐磨材料有限公司 | Process method for refining particle size of CADI (graphite oxide) grinding ball graphite spheres |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101589661A (en) * | 2009-07-01 | 2009-12-02 | 宣化冶金工业有限责任公司 | A kind of Austempering ductile iron ploughshare and production method thereof that has carbide |
| CN104152792A (en) * | 2014-08-16 | 2014-11-19 | 河北工业大学 | Ausferrite ductile cast iron grinding ball |
| CN104233051A (en) * | 2014-08-30 | 2014-12-24 | 广东省工业技术研究院(广州有色金属研究院) | Carbide-containing ausferrite nodular cast iron and preparation method thereof |
| CN104831156A (en) * | 2015-05-11 | 2015-08-12 | 柳州金盾机械有限公司 | Method for micro-alloying treatment of ausferrite ductile cast iron grinding balls |
-
2015
- 2015-08-31 CN CN201510546312.7A patent/CN105132790A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101589661A (en) * | 2009-07-01 | 2009-12-02 | 宣化冶金工业有限责任公司 | A kind of Austempering ductile iron ploughshare and production method thereof that has carbide |
| CN104152792A (en) * | 2014-08-16 | 2014-11-19 | 河北工业大学 | Ausferrite ductile cast iron grinding ball |
| CN104233051A (en) * | 2014-08-30 | 2014-12-24 | 广东省工业技术研究院(广州有色金属研究院) | Carbide-containing ausferrite nodular cast iron and preparation method thereof |
| CN104831156A (en) * | 2015-05-11 | 2015-08-12 | 柳州金盾机械有限公司 | Method for micro-alloying treatment of ausferrite ductile cast iron grinding balls |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106319338A (en) * | 2016-08-31 | 2017-01-11 | 陕西同心连铸管业科技有限公司 | Self-lubricating rolling bearing and preparing method thereof |
| CN106319338B (en) * | 2016-08-31 | 2018-03-20 | 西安理工大学 | A kind of self-lubricating bearing and preparation method thereof |
| US11085097B2 (en) | 2016-08-31 | 2021-08-10 | Xi'an University Of Technology | Self-lubricating rolling bearing and preparation method therefor |
| CN106834902A (en) * | 2017-03-14 | 2017-06-13 | 姜廷敏 | A kind of high-wearing feature carbide-containing ausferrite spheroidal graphite cast iron and preparation method thereof |
| CN106834902B (en) * | 2017-03-14 | 2018-08-10 | 姜廷敏 | A kind of high-wearing feature carbide-containing ausferrite spheroidal graphite cast iron and preparation method thereof |
| CN115216585A (en) * | 2022-07-29 | 2022-10-21 | 宁国市华丰耐磨材料有限公司 | Process method for refining particle size of CADI (graphite oxide) grinding ball graphite spheres |
| CN115216585B (en) * | 2022-07-29 | 2023-07-18 | 宁国市华丰耐磨材料有限公司 | Technological method for refining particle size of CADI grinding ball graphite spheres |
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Effective date of registration: 20160825 Address after: 510651 Changxin Road, Guangzhou, Guangdong, No. 363, No. Applicant after: GUANGDONG INSTITUTE OF MATERIALS AND PROCESSING Address before: 510651 Changxin Road, Guangzhou, Guangdong, No. 363, No. Applicant before: Guangzhou Research Institute of Non-ferrous Metals |
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