CN101220404B - Method for processing nodular cast iron troostite - Google Patents
Method for processing nodular cast iron troostite Download PDFInfo
- Publication number
- CN101220404B CN101220404B CN2007101158050A CN200710115805A CN101220404B CN 101220404 B CN101220404 B CN 101220404B CN 2007101158050 A CN2007101158050 A CN 2007101158050A CN 200710115805 A CN200710115805 A CN 200710115805A CN 101220404 B CN101220404 B CN 101220404B
- Authority
- CN
- China
- Prior art keywords
- temperature
- workpiece
- cooling
- troostite
- coolant water
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Heat Treatment Of Articles (AREA)
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
- Heat Treatment Of Steel (AREA)
- Control Of Heat Treatment Processes (AREA)
Abstract
The invention provides a ductile iron bainite processing method, including the processing steps of: heating up the ductile iron to the austenite region; taking the water as a cooling medium for controlling the cooling, adjusting the even temperature, processing the isothermal and tempering. In the cooling control phase, the cooling control technique parameter is determined by the cooling parameter R. During the even temperature phase, the control temperature is regulated to carry out the isothermal treatment on the work-piece under the condition that the temperature is proximal to the isothermal treatment temperature, thus ensuring the stable technique. The performance of the obtained ductile iron dominated by the super-cooling troostite is close to the bainite ductile iron. With higher stability of the performance, the notch sensitivity of the obtained ductile iron dominated by the super-cooling troostite is lower than that of the bainite ductile iron. The performance of the small-sized part of the work-piece processed by the method is higher than that of the larger-sized part, thereby offering help for solving a plurality of work-pieces that are difficult to process.
Description
Technical field
The invention belongs to metal material field, relate to the spheroidal graphite cast iron heat treating method, specifically a kind of treatment process of spheroidal graphite cast iron troostiteization.
Background technology
Spheroidal graphite cast iron is since last century, came to light the forties; It is used constantly and enlarges; So far become one of important engineering material; The output of whole world spheroidal graphite cast iron has accounted for 1/3 of whole world graphitic cast iron output in recent years, further improves the spheroidal graphite cast iron performance and optimization production technology can be improved the quality of products and reduce cost, and is all significant with the protection environment for reducing resource consumption.High performance spheroidal graphite cast iron can be applied even more extensively with the aspect of iron for steel and casting and forging, to practice thrift the cost savings energy.
In research, relatively pay close attention to bainite matrix and sorbite matrix, and under normal working condition, being not easy to obtain with the troostite is main matrix to the spheroidal graphite cast iron matrix.Because troostite spheroidal graphite cast iron also has its different and bainite and sorbitic property and purposes, for some extraordinary workpiece and industry, what also press for some excellent performances is the ductile cast iron material of main matrix with troostite.
Summary of the invention
In order to satisfy the demand of market, the invention provides the spheroidal graphite cast iron troostite treatment process of a kind of difference and conventional processing mode to high-performance spheroidal graphite cast iron.Conventional processing is main to accelerate speed of cooling refinement slices spacing mainly; The cold troostite spheroidal graphite cast iron of mistake that treatment process of the present invention obtains utilizes controlled chilling in the hope of farthest increasing condensate depression, refinement troostite group; The refinement slices spacing, obtaining to cross cold troostite is master's spheroidal graphite cast iron.Its performance is near bainite ductile iron, and its notch sensitivity is lower than bainite ductile iron and stability is higher.The workpiece of particularly handling in this way, the performance at small size position will be higher than the large size position, for solving some difficult workpiece of handling help is provided.
The present invention is a kind of spheroidal graphite cast iron troostite treatment process, comprises spheroidal graphite cast iron is heated to the austenitic area, uses water as the heat-eliminating medium controlled chilling, workpiece packed into accomplish the troostite isothermal transformation in the constant-temperature oven, and its process step and working method are following:
A. ductile iron workpiece is heated to the austenitic area, and homogenizing;
B. controlled chilling: as heat-eliminating medium, coolant water temperature is selected 20 ℃-100 ℃ for use with water; Size and dimension according to workpiece is different, confirms the technology for controlled cooling of workpiece, with workpiece controlled chilling zone to the troostite district, more than the Ms point, is as the criterion so that workpiece temperature gos up to get into the troostite district;
C. cross cold, the adjustment of rising again: after the workpiece water outlet, controlled temperature gos up to reach 550 ℃～600 ℃, makes controlled chilling and condensate depression reach desirable and cooperates; When temperature recovery is too high, adopt mode air-cooled or spraying to adjust control;
D. isothermal processes: rise again be adjusted to 550～600 ℃ after, be in the constant-temperature oven of bainite isothermal region with the workpiece design temperature of packing into, accomplish structural transformation;
E. tempering: require to select high temperature or middle temperature or low-temperaturetempering or not tempering according to workpiece.
Spheroidal graphite cast iron troostite treatment process as stated, said size and dimension according to workpiece is different among its step b, confirms that the concrete grammar of technology for controlled cooling of workpiece is following:
Set pending workpiece volume V and pending workpiece surface-area A liken cooling parameter R to into this workpiece, utilize formula R=V/A, calculate the concrete numerical value of the cooling parameter R of pending workpiece; According to the size of pending work-piece cools parameters R, confirm required coolant water temperature of controlled chilling stage and cooling time; Cooling parameter R is higher, and required coolant water temperature is lower; Cooling parameter R is lower, and required coolant water temperature is higher.
According to cooling parameter R value, confirm that the span of control of coolant water temperature is following:
The span of control of coolant water temperature is 40 ℃～80 ℃ when R≤10;
The span of control of coolant water temperature is 20 ℃-60 ℃ when R＞10;
Differ bigger workpiece for complex-shaped, size thickness, select 60 ℃-100 ℃ of demulcent coolant water temperatures for use;
According to cooling parameter R value, confirm that preparatory controlled chilling amplitude is following:
Small-sized sample (R≤10) is estimated controlled chilling workpiece surface temperature to 500 ℃-400 ℃; It is the district of going up of upper bainite;
Medium-sized sample (10≤R>=20) is estimated controlled chilling workpiece surface temperature to 450 ℃-350 ℃; It is the middle inferior segment of upper bainite;
Large-scale sample (R >=20) is estimated controlled chilling workpiece surface temperature to 400 ℃-300 ℃; It is the inferior segment of upper bainite;
Specifically corresponding to various coolant water temperatures required cooling times, select to use the basic workpiece corresponding cooling time identical or close in the fundamental technology data sheet of this coolant water temperature with the cooling parameter R of pending workpiece.
As stated in the spheroidal graphite cast iron troostite treatment process said step c rise again the adjustment working method following:
After the water outlet of controlled chilling workpiece, with surface temperature measurement apparatus measures temperature recovery scope, the workpiece surface maximum temperature gos up to reach 550 ℃-600 ℃, and the constant-temperature oven of directly packing into is handled; Surpass this TR, adopt mode air-cooled or spraying to adjust; Because the temperature difference at internal-external temperature difference and thickness position makes that small size position temperature recovery is big, condensate depression is big; Large size position temperature recovery is little, and condensate depression is relatively little, and the adjustment thermometric is as the criterion with the small size position.Above process step is as the criterion so that workpiece temperature gos up to get into the troostite district.
The working method of said steps d isothermal processes is following in the spheroidal graphite cast iron troostite treatment process as stated:
Workpiece is adjusted to 550 ℃～600 ℃ through rising again after, the design temperature of packing into is in the constant-temperature oven of bainite isothermal region, accomplishes structural transformation;
According to the size of work-piece cools parameters R value, it is following to set the isothermal treatment temperatures scope respectively:
Reduced size workpiece R≤10 are chosen in 400 ℃ of-330 ℃ of isothermals in upper bainite district;
Large-size workpiece appearance R >=10 are chosen in 330 ℃ of-250 ℃ of isothermals in lower bainite district;
The present invention is set in bainite district (400 ℃-250 ℃) with isothermal treatment temperatures rather than in the troostite district (550 ℃-600 ℃), based on following 3 points:
1. after getting into constant-temperature oven, hoping that workpiece temperature is gone up does not continue but gradual slow descends, because of the troostite velocity of transformation than very fast; 2. present method crosses that cool tone is whole to be as the criterion with the small size position, can make the thick position of workpiece and heart portion continuation radiating and cooling, obtains thin troostite or sorbite as far as possible; If 3. troostite changes not exclusively, it is also favourable to performance to obtain a small amount of bainite, prevents martensite.
Spheroidal graphite cast iron troostite treatment process as stated, said definite technology for controlled cooling among its step b, the practical implementation step of promptly required coolant water temperature and cooling time is following:
(1) set up the fundamental technology data sheet:
A. basic specimen size is set at Φ dxd, presses the concrete size of d, makes a series of basic sample;
B. according to formula R=V/A, calculate the cooling parameter R of each basic sample respectively;
C. be determined at respectively under the various coolant water temperature through experiment, reach and estimate controlled chilling workpiece surface temperature needed cooling time;
D. be unit with the coolant water temperature, basic specimen size, cooling parameter R and the cooling time corresponding with it listed in the table, thereby made a series of fundamental technology data sheet;
(2) utilize the cooling parameter R and the fundamental technology data sheet of pending workpiece, confirm required coolant water temperature of controlled chilling stage and cooling time:
A. by formula R=V/S calculates the cooling parameter R of pending workpiece;
B. according to the numerical values recited of cooling parameter R, confirm needed coolant water temperature;
C. in the fundamental technology data sheet of required coolant water temperature, search the cooling time of the basic sample identical or close, be pending workpiece required cooling time with the cooling parameter R of pending workpiece.So that ging up to get into the troostite district, workpiece temperature is as the criterion;
Said tempering step in the spheroidal graphite cast iron troostite treatment process as stated; Can require selections needs temper or needn't tempering according to workpiece, like the need tempering, after the isothermal transformation of workpiece completion troostite; As requested, select high temperature or middle temperature or low-temperaturetempering to handle.Low-temperaturetempering can partly eliminate stress, and high tempering (550 ℃-720 ℃, water-cooled or oil cooling after the tempering) raises with tempering temperature, and tensile strength reduces, and unit elongation raises.
Treatment process of the present invention; All adopted and ordinary method different technological conditions and processing mode adjustment and three of isothermal processes the treatment stage controlled chilling, cold excessively rising again; In the controlled chilling stage; According to the cooling parameter R of workpiece, screen each item processing parameters such as controlled chilling water temperature, cooling time and expectation controlled chilling temperature accurately, reasonably, farthest cause big condensate depression; Maximum temperature gos up to reach 550 ℃～600 ℃ and cooperates with big condensate depression formation ideal, more helps the transformation of troostite.Cool off+rise again adjustment+isothermal processes associated treatment by control, excite the nucleation rate that has increased troostite, make troostite group more tiny, performance is more stable, and can obtain is the spheroidal graphite cast-iron of matrix to cross cold troostite mainly.The shrinkage cavity that its fracture subsurface exists, defective such as loose are lower than bainite ductile iron to the susceptibility of its performance impact.It is better that this method is used for the local performance of size uneven part better effects if, particularly widget.
The cold excessively processing method of rising again according to the invention also can be used for the processing of steel.
Description of drawings
Accompanying drawing 1 is the ductile iron workpiece size shape figure that gives an example among the embodiment 2 and handle
Embodiment
Embodiment 1 fundamental technology data sheet (instance)
Table 1: the key dimension sample, 40 ℃ of coolant water temperatures,, cooling time (second) and expectation cooling temperature
Annotate: this table need make successively serial key dimension and a plurality of water temperature (20,30,40,50 ...) data sheet
Embodiment 2
Ductile iron workpiece, (nodulizing grade; 2 grades, the graphite size; 6 grades)
Size shape is shown in accompanying drawing 1;
Technological process;
1. select preparatory technology for controlled cooling parameter;
1. calculate the workpiece radiation parameter R of this workpiece, R=V/S R=8.5
Belong to small-sized sample (R≤10), estimate controlled chilling to 500 ℃-400 ℃ (going up of upper bainite distinguished).
2. table look-up 1; The radiation parameter R=8.5 of workpiece is close with the R=8.33 of key dimension sample Φ 50 * 50mm.Therefore can formulate preparatory technology for controlled cooling with reference to Φ 50 * 50mm sample data.
3. by table 1; Φ 50 * 50mm sample is cooled to the upper bainite district, and 40 ℃ of water need cool off 10s-15s, gets Qi Shang district 10s.
2. thermal treatment; Heating; 880 ℃, be incubated 1 hour.
Cooling; With 40 ℃ of water, take out behind the cooling 10s.
3. adjustment; After workpiece takes out, measure the small size position with the surface temperature measurement appearance, temperature recovery is from 450 ℃-660 ℃.Need slightly adjust.Rise again and in incubation period, accomplish.
Take out behind the adjustment cooling 11s, measure temperature recovery, do not need adjustment, can directly advance constant-temperature oven from 410 ℃-590 ℃.
4. isothermal; The isothermal furnace temperature is selected 370 ℃ for use, is incubated 1 hour, takes out.
5. tempering; 200 ℃ of tempering, 1 hour.
6. check;
Tissue; The small size position is tiny troostite basically, and troostite group is tiny.The large size position is troostite+sorbite.
Performance; The small size position, tensile strength 1020MPa, unit elongation 4%.Hardness 34.8HRc.Large size position hardness 33.2HRc
Claims (2)
1. spheroidal graphite cast iron troostite treatment process comprises spheroidal graphite cast iron is heated to the austenitic area, uses water as the heat-eliminating medium controlled chilling, workpiece packed into accomplish the troostite isothermal transformation in the constant-temperature oven, it is characterized in that process step and working method are following:
A. ductile iron workpiece is heated to the austenitic area, and homogenizing;
B. controlled chilling: as heat-eliminating medium, coolant water temperature is selected 20 ℃-100 ℃ for use with water; Size and dimension according to workpiece is different, confirms the technology for controlled cooling of workpiece, with workpiece controlled chilling zone to the troostite district, more than the Ms point, is as the criterion so that workpiece temperature gos up to get into the troostite district;
Concrete grammar is following: set pending workpiece volume V and pending workpiece surface-area A liken cooling parameter R to into this workpiece, utilize formula R=V/A, calculate the concrete numerical value of the cooling parameter R of pending workpiece; According to the size of pending work-piece cools parameters R, confirm required coolant water temperature of controlled chilling stage and cooling time; Cooling parameter R is higher, and required coolant water temperature is lower; Cooling parameter R is lower, and required coolant water temperature is higher;
According to cooling parameter R value, confirm that the span of control of coolant water temperature is following:
The span of control of coolant water temperature is 60～80 ℃ when R≤10;
The span of control of coolant water temperature is 20-60 ℃ when R＞10;
Differ bigger workpiece for complex-shaped, size thickness, select 60 ℃-100 ℃ of demulcent coolant water temperatures for use;
Specifically corresponding to various coolant water temperatures required cooling times, select to use the basic workpiece corresponding cooling time identical or close in the fundamental technology data sheet of this coolant water temperature with the cooling parameter R of pending workpiece;
C. cross cold, the adjustment of rising again: after the workpiece water outlet, controlled temperature gos up to reach 550～600 ℃, makes controlled chilling and condensate depression reach desirable and cooperates; When temperature recovery is too high, adopt mode air-cooled or spraying to adjust control;
D. isothermal processes: rise again be adjusted to 550～600 ℃ after, be in the constant-temperature oven of bainite isothermal region with the workpiece design temperature of packing into, accomplish isothermal transformation;
E. tempering: require to select high temperature or middle temperature or low-temperaturetempering or not tempering according to workpiece.
2. spheroidal graphite cast iron troostite treatment process according to claim 1 is characterized in that said step c is cold excessively, the working method of the adjustment of rising again is following:
After the water outlet of controlled chilling workpiece, with surface temperature measurement apparatus measures temperature recovery scope, the workpiece surface maximum temperature gos up to reach 550 ℃-600 ℃, and the constant-temperature oven of directly packing into is handled; Surpass this TR, adopt mode air-cooled or spraying to adjust; Because the temperature difference at internal-external temperature difference and thickness position makes that small size position temperature recovery is big, condensate depression is big, and large size position temperature recovery is little, and condensate depression is relatively little, and the adjustment thermometric is as the criterion with the small size position.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007101158050A CN101220404B (en) | 2007-12-20 | 2007-12-20 | Method for processing nodular cast iron troostite |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007101158050A CN101220404B (en) | 2007-12-20 | 2007-12-20 | Method for processing nodular cast iron troostite |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101220404A CN101220404A (en) | 2008-07-16 |
| CN101220404B true CN101220404B (en) | 2012-01-25 |
Family
ID=39630480
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007101158050A Expired - Fee Related CN101220404B (en) | 2007-12-20 | 2007-12-20 | Method for processing nodular cast iron troostite |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101220404B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103215430A (en) * | 2013-04-23 | 2013-07-24 | 冯伟年 | Novel technique for isothermal heat treatment of steel wire |
| CN107922991B (en) * | 2015-09-30 | 2020-02-14 | 日立金属株式会社 | Method for deriving cooling time in quenching steel material, method for quenching steel material, and method for quenching and tempering steel material |
| CN116103474A (en) * | 2020-03-02 | 2023-05-12 | 中车戚墅堰机车车辆工艺研究所有限公司 | Heat treatment method for ductile iron castings and ductile iron castings obtained thereby |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1718768A (en) * | 2005-07-20 | 2006-01-11 | 山东建筑工程学院材料科学研究所 | Bainite auctile iron isothermal quenching technology |
-
2007
- 2007-12-20 CN CN2007101158050A patent/CN101220404B/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1718768A (en) * | 2005-07-20 | 2006-01-11 | 山东建筑工程学院材料科学研究所 | Bainite auctile iron isothermal quenching technology |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101220404A (en) | 2008-07-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103866095B (en) | A kind of spheroidizing method for being directed to Cr, Mo steel with sheet microstructure | |
| CN104946870A (en) | Heat treatment method for strength of 28CrMoNiV steel capable of improving industrial steam turbine rotor forge piece | |
| CN103014283B (en) | Manufacture method of extremely-thick steel plate for hydropower station through continuous-cast billet | |
| CN105886717B (en) | A kind of residual forging heat normalizing method of steel | |
| CN103421940A (en) | Technological method for AISI4140 and AISI 4340 constructional steel forged piece quenching and tempering through one-time thermal cycling | |
| CN110257617A (en) | The forging of big specification 20SiMn main shaft and heat treatment method | |
| CN103469092A (en) | Production method for main shaft of fan by using 34CrNiMo6 steel as raw material | |
| CN103333997A (en) | Annealing heat treatment method of H13 die steel | |
| CN108085591A (en) | A kind of steel plate HTNM400 and its production method with low-welding crack-sensitive energy | |
| CN101220404B (en) | Method for processing nodular cast iron troostite | |
| CN102676780A (en) | Hardening and tempering technology of alloy-steel tube | |
| Gorbatyuk et al. | Reindustrialization principles in the heat treatment of die steels | |
| CN101220403B (en) | Isothermal treatment method for nodular cast iron bainite | |
| CN108330386B (en) | Steel for saw blade and production method of hot rolled steel plate thereof | |
| CN101524813B (en) | Waste heat hardening and tempering process of motorcycle crank forged piece | |
| CN110484701A (en) | A kind of heat treatment process of the low deformation rate of large die-casting mould steel high tenacity | |
| CN108031779A (en) | A kind of turbine blade and preparation method thereof | |
| CN114317932A (en) | Heat treatment method for obtaining balanced structure of thick-wall high-cylinder ring forging | |
| CN104745787B (en) | Production method of tool steel capable of being directly cold rolled | |
| CN104789748A (en) | Bearing steel tube spheroidizing annealing method | |
| CN111445960B (en) | Method for optimizing forging technological parameters of 14Cr17Ni2 steel | |
| CN103320686B (en) | Cold rolled sheet No. 45 steel and production method thereof | |
| CN104451100A (en) | Heat treatment method of seamless steel pipe | |
| CN104232858A (en) | Spheroidizing annealing technology of high-tenacity fastener wire rod | |
| CN105018712A (en) | Spheroidizing annealing process of superplastic medium carbon steel wire |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| ASS | Succession or assignment of patent right |
Owner name: SHANDONG CONSTRUCTION UNIVERSITY Free format text: FORMER OWNER: MATERIALS INST, SHANDONG ARCHITECHTURE UNIV. Effective date: 20111201 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| C53 | Correction of patent for invention or patent application | ||
| CB03 | Change of inventor or designer information |
Inventor after: Liu Kegao Inventor after: Xu Aimin Inventor before: Xu Aimin Inventor before: Liu Kegao |
|
| COR | Change of bibliographic data |
Free format text: CORRECT: INVENTOR; FROM: XU AIMIN LIU KEGAO TO: LIU KEGAO XU AIMIN |
|
| TA01 | Transfer of patent application right |
Effective date of registration: 20111201 Address after: Fengming Road District of Ji'nan City, Shandong province 250101 No. 13 port development Applicant after: Shandong Construction University Address before: Fengming Road District of Ji'nan City, Shandong province 250101 No. 13 port development Applicant before: Materials Inst, Shandong Architechture Univ. |
|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120125 Termination date: 20121220 |