CN103555905A - Method for obtaining ferritic heat-resisting steel with the characteristic of austenite structure - Google Patents
Method for obtaining ferritic heat-resisting steel with the characteristic of austenite structure Download PDFInfo
- Publication number
- CN103555905A CN103555905A CN201310507649.8A CN201310507649A CN103555905A CN 103555905 A CN103555905 A CN 103555905A CN 201310507649 A CN201310507649 A CN 201310507649A CN 103555905 A CN103555905 A CN 103555905A
- Authority
- CN
- China
- Prior art keywords
- steel
- deformation
- room temperature
- austenite structure
- heat
- 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.)
- Granted
Links
Images
Landscapes
- Heat Treatment Of Articles (AREA)
Abstract
The invention relates to a method for obtaining ferritic heat-resisting steel with the characteristics of an austenite structure, and belongs to the technical field of heat-resisting steels. A large deformation+heat treatment process is adopted, and the technical parameters controlled in process steps are as follows: heating 9%-12% Cr steel to 1100-1200 DEG C at 20 DEG C/s, and keeping temperature for 30-120 minutes; then cooling to 500-800 DEG C at 10 DEG C/s, keeping the temperature for 3-15 seconds, deforming at the deformation rate of 1s<-1> and the deformation amount of 70%-90%, immediately quenching to room temperature after the deformation is completed; then tempering at 650-800 DEG C for 1-5 hours, and air-cooling to room temperature. The method disclosed by the invention is used for preparing the 9%-12% Cr steel and a large-caliber boiler pipe thereof. According to the invention, the initial size of a precipitated phase is obviously thinner than the initial size of a precipitated phase treated through the traditional heat treatment mechanism, a ferrite structure has characteristics similar to the characteristics of the austenite structure, belongs to an equilibrium state and is small in interface quantity and less in diffusion channel; a base body has good structure stability in a long-time service process.
Description
Technical field
The invention belongs to high temperature steel technical field, a kind of method that particularly provides acquisition to have the jessop of austenite structure feature, can be used for 9-12%Cr steel and the preparation of heavy caliber boi1er tube thereof.
Background technology
In recent years, ultra supercritical thermal power station construction demand increases rapidly, along with the raising of vapor temperature and pressure, ultra supercritical fired power generating unit is had higher requirement to the performance of heat-stable material, is mainly manifested in the following aspects: the high-temperature and durable that (1) is higher and creep strength; (2) excellent structure stability; (3) good hot and cold processing characteristics; (4) good anti-oxidant and corrosion resisting property; (5) good welding property etc.
The alloy content of 9-12%Cr steel is low, and cost advantage is large, and meanwhile, thermal expansivity is low, and thermal conductivity is high.The matrix of 9-12%Cr steel is all generally tempered martensite, there are a large amount of dislocations and precipitated phase simultaneously, strengthening mechanism is various, and very important effect is all played in solution strengthening, dislocations strengthening, dispersion-strengthened and substructure strengthening, has well embodied " polynary complex intensifying " theory.But tempered martensite is nonequilibrium state, the equilibrium state of 9-12%Cr steel is ferrite.Therefore, martensite heat-resistant steel can change to equilibrium state (ferrite) after being on active service when long gradually, and a large amount of replies that are accompanied by dislocation are buried in oblivion, precipitated phase alligatoring, separating out of substructure reply and solid solution element, thus material property is weakened, finally cause failure fracture.Wherein, the alligatoring of precipitated phase and the reply of substructure are very important induction factors.In martensite heat-resistant steel, there is a large amount of substructures: original austenite (prior austenite grain, PAG), lath bundle (packet), lath block (block) and lath (lath), have a large amount of dislocations between lath.Therefore, have a large amount of interfaces and dislocation in martensite heat-resistant steel, these interfaces and dislocation provide good diffusion admittance, have promoted to a certain extent the alligatoring of precipitated phase.Meanwhile, interface and number of dislocations are many, have also increased the motivating force of its reply, promote the deterioration of performance.Compare with martensite heat-resistant steel, the advantage of austenitic heat-resistance steel is that it organizes singlely, is all austenite structure, there is no substructure, is exactly equilibrium state at the beginning of under arms, does not exist nonequilibrium state to the transformation of equilibrium state.Meanwhile, on the crystal boundary of austenitic heat-resistance steel and matrix, have a large amount of precipitation hardened, so under high temperature its durable creeping performance significantly better than martensite heat-resistant steel.But the shortcoming of austenitic heat-resistance steel is that alloy content is higher, cost also so higher.Thermal expansivity is large, and heat-conduction coefficient is low.Can so, abandon the shortcoming of two kinds of high temperature steel simultaneously in conjunction with the advantage of austenitic heat-resistance steel and martensite heat-resistant steel, maximize favourable factors and minimize unfavourable ones, be the main points that the present invention studies.
The people such as Toda find under study for action, can obtain single ferritic structure or ferrite+martensite, to substitute the single martensitic stucture of 9-12% steel in 15%Cr steel by adding W and Co.The enduring quality of single ferritic structure or ferrite+martensitic stucture is obviously better than single martensitic stucture (details are shown in the document that the people such as Toda deliver in recent years).Ferritic structure is equilibrium state, has austenitic tissue signature, and wherein martensite substructure is few, matrix can not occur in military service process when long and change, and does not therefore also have the degeneration of tissue.
Summary of the invention
The object of the present invention is to provide a kind of acquisition to there is the method for the jessop of austenite structure feature, acquisition has the 9-12%Cr jessop of austenite structure feature, be applicable to the heavy caliber boi1er tube of advanced ultra supercritical fired power generating unit and the manufacture of associated conduit, can improve the service temperature of this high temperature steel.
The present invention, in conjunction with this research team existing 9-12%Cr martensitic steel Research foundation, under the composition of existing 9-12%Cr steel, by gross distortion+heat treated mode, makes this steel obtain a kind of stable ferritic structure with austenite structure feature.Meanwhile, due to the factor of gross distortion, precipitated phase (M especially
23c
6) obtained obvious refinement, the M of these refinements
23c
6be distributed on crystal boundary and matrix in, strengthened well crystal boundary and matrix.Because interface and the number of dislocations of ferrite matrix is all starkly lower than martensitic matrix, so diffusion admittance is few, and when long, in military service process, the alligatoring speed of precipitated phase has also obtained better inhibition, has played good strengthening effect.The present invention can further improve the service temperature of 9-12%Cr high temperature steel.
The present invention adopts gross distortion+process of thermal treatment: the technical parameter of controlling in concrete technology step is: 9-12%Cr steel is heated to 1100-1200 ℃ with 20 ℃/s, insulation 30-120min; Then, with 10 ℃/s, be cooled to 500-800 ℃, insulation 3-15s, take rate of deformation as 1s
-1be out of shape, deflection is 70-90%, is quenched to immediately room temperature after being out of shape, and then, at 650-800 ℃ of tempering 1-5 hour, air cooling is to room temperature.
9-12%Cr steel is after gross distortion+thermal treatment of the present invention, and the obvious refinement of the original dimension of precipitated phase has obtained the ferritic structure with austenite structure feature simultaneously.Ferritic structure is the equilibrium state tissue of 9-12%Cr steel, has good structure stability.In addition, compare with martensitic stucture, because ferritic structure does not have substructure, number of interfaces is few, and diffusion admittance is few, and when long, in military service process, the alligatoring speed of precipitated phase is slow, and strengthening effect is good.Therefore, gross distortion+thermal treatment process of the present invention has improved the high temperature endurance performance of 9-12%Cr high temperature steel, can further improve its service temperature.
Compared with prior art, advantage of the present invention is:
(1) through the sample after gross distortion+thermal treatment of the present invention, the obvious refinement of precipitated phase original dimension after the original dimension of precipitated phase is processed than prior heat treatment system.
(2) through the sample after gross distortion+thermal treatment of the present invention, matrix is ferritic structure, and prior heat treatment matrix of samples is afterwards tempered martensite.Ferritic structure has the feature that is similar to austenite structure, belongs to equilibrium state, and number of interfaces is few, and diffusion admittance is few.When long, in military service process, matrix has good structure stability, and the alligatoring speed of precipitated phase also obtained better inhibition, has played good strengthening effect.Can further improve the service temperature of 9-12%Cr high temperature steel.
Accompanying drawing explanation
Fig. 1 is the SEM photo of the embodiment of the present invention 1.
Fig. 2 is the SEM photo of the embodiment of the present invention 2.
Fig. 3 is the SEM photo of the embodiment of the present invention 3.
Fig. 4 is the EBSD photo of the embodiment of the present invention 1.
Fig. 5 is the EBSD photo of the embodiment of the present invention 2.
Fig. 6 is the EBSD photo of the embodiment of the present invention 3.
Embodiment
Select inventor's invention steel G115 steel before as concrete enforcement material, composition is as shown in table 1.
The composition of high temperature steel in table 1 embodiment
Gross distortion+process of thermal treatment of the present invention is: with 20 ℃/s, be heated to 1100-1200 ℃, insulation 30-120min; Then, with 10 ℃/s, be cooled to 500-800 ℃, insulation 3-15s, take rate of deformation as 1s
-1be out of shape, deflection is 70-90%, is quenched to immediately room temperature after being out of shape, and then, at 650-800 ℃ of tempering 1-5 hour, air cooling is to room temperature.
Be below specific embodiments of the invention, but the invention is not restricted to following embodiment.
Embodiment 1:
The composition of jessop, in Table 1, is quenched to immediately room temperature by this high temperature steel after 1100 ℃ of insulation 60min.Then 780 ℃ of tempering 3 hours, air cooling was to room temperature.Embodiment 1 is prior heat treatment system, in order to compare with the gross distortion+thermal treatment process of the present invention of embodiment 2 and 3.
Embodiment 2:
The composition of jessop, in Table 1, is processed into this high temperature steel on the right cylinder sample of Φ 8 * 15mm, carries out the experiment of gross distortion+thermal treatment process on Gleeble3800 type hot modeling test machine, the steps include: to be heated to 1100 ℃ with 20 ℃/s insulation 90min; Then, with 10 ℃/s, be cooled to 600 ℃, insulation 10s, take rate of deformation as 1s
-1carry out compression set, deflection is 70%, is quenched to immediately room temperature after being out of shape.Then 750 ℃ of tempering 2 hours, air cooling was to room temperature.
Embodiment 3:
The composition of jessop, in Table 1, is processed into this high temperature steel on the right cylinder sample of Φ 8 * 15mm, carries out the experiment of gross distortion+thermal treatment process on Gleeble3800 type hot modeling test machine, the steps include: to be heated to 1150 ℃ with 20 ℃/s insulation 40min; Then, with 10 ℃/s, be cooled to 700 ℃, insulation 5s, take rate of deformation as 1s
-1carry out compression set, deflection is 80%, is quenched to immediately room temperature after being out of shape.Then 700 ℃ of tempering 4 hours, air cooling was to room temperature.
Embodiment 1 use be prior heat treatment process, as comparing with gross distortion+thermal treatment process of the present invention.Embodiment 2 and 3 use be gross distortion+thermal treatment process of the present invention.Sample after above-mentioned thermal treatment is carried out to tissue topography's analysis by SEM and EBSD.Fig. 1 is the SEM tissue topography of embodiment 1, and Fig. 2 is the SEM tissue topography of embodiment 2, and Fig. 3 is the SEM tissue topography of embodiment 3.From Fig. 1-3, can observe, through the sample after gross distortion+thermal treatment of the present invention, the size of precipitated phase is compared and has been obtained obvious refinement with the precipitate size after prior heat treatment.Fig. 4 is the EBSD tissue topography of embodiment 1, and Fig. 5 is the EBSD tissue topography of embodiment 2, and Fig. 6 is the EBSD tissue topography of embodiment 3.As can be seen from Figure 4, the sample after prior heat treatment, is organized as typical tempered martensite, and panel construction is clear.And can find out from Fig. 5 and Fig. 6, the sample through after gross distortion+thermal treatment of the present invention, is organized as typical ferritic structure, and the basic completely dissolve of substructure only has interface, big angle to exist.This is very similar to organizing of austenitic steel.Therefore think, through gross distortion+thermal treatment of the present invention, can successfully obtain the 9-12%Cr jessop with austenite structure feature.
In sum, 9-12%Cr steel is after gross distortion+thermal treatment of the present invention, and the obvious refinement of the original dimension of precipitated phase has obtained the ferritic structure with austenite structure feature simultaneously.Ferritic structure is the equilibrium state tissue of 9-12%Cr steel, has good structure stability.In addition, compare with martensitic stucture, because ferritic structure does not have substructure, number of interfaces is few, and diffusion admittance is few, and when long, in military service process, the alligatoring speed of precipitated phase is slow, and strengthening effect is good.Therefore, gross distortion+thermal treatment process of the present invention has improved the high temperature endurance performance of 9-12%Cr high temperature steel, can further improve its service temperature.
Claims (1)
1. acquisition has a method for the jessop of austenite structure feature, adopts gross distortion+process of thermal treatment; It is characterized in that, the technical parameter of controlling in processing step is: 9-12%Cr steel is heated to 1100-1200 ℃ with 20 ℃/s, insulation 30-120min; Then, with 10 ℃/s, be cooled to 500-800 ℃, insulation 3-15s, take rate of deformation as 1s
-1be out of shape, deflection is 70-90%, is quenched to immediately room temperature after being out of shape, and then, at 650-800 ℃ of tempering 1-5 hour, air cooling is to room temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310507649.8A CN103555905B (en) | 2013-10-24 | 2013-10-24 | Method for obtaining ferritic heat-resisting steel with the characteristic of austenite structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310507649.8A CN103555905B (en) | 2013-10-24 | 2013-10-24 | Method for obtaining ferritic heat-resisting steel with the characteristic of austenite structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103555905A true CN103555905A (en) | 2014-02-05 |
| CN103555905B CN103555905B (en) | 2015-07-01 |
Family
ID=50010248
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310507649.8A Active CN103555905B (en) | 2013-10-24 | 2013-10-24 | Method for obtaining ferritic heat-resisting steel with the characteristic of austenite structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103555905B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108998650A (en) * | 2018-07-10 | 2018-12-14 | 内蒙古北方重工业集团有限公司 | 630 DEG C of extra-supercritical unit G115 method for manufacturing large-diameter thick-wall seamless steel pipe |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002332547A (en) * | 2001-05-09 | 2002-11-22 | Sumitomo Metal Ind Ltd | Ferritic heat resistant steel having little softening in heat affected zone |
| CN101899556A (en) * | 2010-08-11 | 2010-12-01 | 内蒙古北方重工业集团有限公司 | Heat treatment method for thinning coarse grains of ferrite refractory steel for bearing pressure at high temperature |
| CN102994888A (en) * | 2012-11-27 | 2013-03-27 | 天津大学 | Novel high-chromium ferritic heat resistant steel and thermo-mechanical treatment process |
| CN103045962A (en) * | 2012-12-26 | 2013-04-17 | 钢铁研究总院 | Steel for steam-temperature ultra-supercritical thermal power unit and preparation method thereof |
| CN103290184A (en) * | 2013-05-29 | 2013-09-11 | 清华大学 | Thermal processing method of chromium-containing ferrite refractory steel |
-
2013
- 2013-10-24 CN CN201310507649.8A patent/CN103555905B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002332547A (en) * | 2001-05-09 | 2002-11-22 | Sumitomo Metal Ind Ltd | Ferritic heat resistant steel having little softening in heat affected zone |
| CN101899556A (en) * | 2010-08-11 | 2010-12-01 | 内蒙古北方重工业集团有限公司 | Heat treatment method for thinning coarse grains of ferrite refractory steel for bearing pressure at high temperature |
| CN102994888A (en) * | 2012-11-27 | 2013-03-27 | 天津大学 | Novel high-chromium ferritic heat resistant steel and thermo-mechanical treatment process |
| CN103045962A (en) * | 2012-12-26 | 2013-04-17 | 钢铁研究总院 | Steel for steam-temperature ultra-supercritical thermal power unit and preparation method thereof |
| CN103290184A (en) * | 2013-05-29 | 2013-09-11 | 清华大学 | Thermal processing method of chromium-containing ferrite refractory steel |
Non-Patent Citations (1)
| Title |
|---|
| 宁保群等: "形变热处理工艺(TMTP)对T91钢显微组织的影响", 《材料热处理学报》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108998650A (en) * | 2018-07-10 | 2018-12-14 | 内蒙古北方重工业集团有限公司 | 630 DEG C of extra-supercritical unit G115 method for manufacturing large-diameter thick-wall seamless steel pipe |
| CN108998650B (en) * | 2018-07-10 | 2023-02-28 | 内蒙古北方重工业集团有限公司 | Method for manufacturing large-caliber thick-wall seamless steel pipe of 630 ℃ ultra-supercritical unit G115 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103555905B (en) | 2015-07-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103898426B (en) | A kind of thermal treatment process of being out of shape ferronickel refractory Cr-base alloy | |
| CN106048486A (en) | Structure refinement method for Ti2AlNb alloy through (O+B2) two-phase region aging treatment | |
| CN105177257A (en) | High-nitrogen nickel-free austenitic stainless steel intergranular-corrosion-prevention processing technology | |
| CN104846273A (en) | Low-temperature plasticity high manganese steel plate and processing technology thereof | |
| CN105177262A (en) | Method for increasing proportion of special grain boundaries in precipitation strengthened austenitic heat-resistance steel | |
| CN106854733B (en) | A kind of manufacturing process of 14Cr17Ni2 stainless steels heavy forging | |
| CN114807741B (en) | Method for improving austenitic stainless steel performance based on carbide precipitation | |
| CN109457201A (en) | A method of refinement nickel-base alloy forging crystal grain simultaneously improves structural homogenity | |
| CN105734249A (en) | Method for refining grain size of large 1Cr11Ni2W2MoV shaft forge pieces | |
| CN108728611A (en) | A kind of martensite heat-resistant steel large-sized heavy-wall tube crystal fining method | |
| CN102899564A (en) | Extra-deep drawing Ti+Nb-IF steel cold rolling and annealing process | |
| Liu et al. | Kinetics of isochronal austenization in modified high Cr ferritic heat-resistant steel | |
| CN103555905B (en) | Method for obtaining ferritic heat-resisting steel with the characteristic of austenite structure | |
| CN102758068A (en) | Heat treatment method of GCr15 steel | |
| CN103589839A (en) | Heat treatment technique of high-carbon high-chromium stainless steel | |
| CN103911493A (en) | Forged NiCrMoV steel piece heat-treatment method and forged piece | |
| CN101892373A (en) | Heat treatment technology for low-temperature high impact toughness medium-thickness steel plate | |
| CN105177445B (en) | A kind of preparation method of high tenacity 3.5Ni steel plates | |
| CN113528979B (en) | High-strength RAFM steel with optimized components and heat treatment process thereof | |
| CN109932388A (en) | A kind of Electroplastic fuel factor and non-thermal effect decouple separation method | |
| CN104263998B (en) | A kind of Technology for Heating Processing of ni-fe-cr-boron system high temperature alloy | |
| CN103938113A (en) | Low-temperature stainless steel and heat treatment method thereof | |
| CN104805264A (en) | Heat treatment method for 15NiCuMoNb5 steel pipe | |
| CN110016543B (en) | Reinforced Ni47Ti44Nb9Method for shape memory performance of alloy pipe joint | |
| Zhan et al. | The Effect of Ageing Treatment on Shape‐Setting and Shape Memory Effect of a NiTi SMA Corrugated Structure |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |