CN104164548A - Heat treatment process of heavy section low-carbon and low-alloy steel castings and forgings - Google Patents
Heat treatment process of heavy section low-carbon and low-alloy steel castings and forgings Download PDFInfo
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Abstract
The invention belongs to the field of heat treatment of steel materials, and particularly relates to a heat treatment process of heavy section low-carbon and low-alloy steel castings and forgings, and is suitable for solving the problem of low low-temperature impact toughness and instability caused by halfway quenching of core parts during the heat treatment of heavy section low-carbon and low-alloy steel castings and forgings. The heat treatment process is characterized by adding one annealing treatment at a temperature of 50-90 DEG C below Acl and one intermediate heat treatment at a temperature of Ac3+/-25 DEG C between conventional quenching and tempering treatment, and accordingly, adjusting the tempering temperature of a conventional process, so as to achieve the object of adjusting content, size, carbon concentration, hardness and distribution position of a martensite/austenite island structure (for short, M-A island) in a granular bainite structure of heavy section central part through the intermediate heat treatment, thereby realizing good matching with a matrix structure and further enabling the central parts of the heavy section steel castings and forgings to have excellent toughness by controlling evolution of a granular bainite matrix and the M-A island in the tempering process through proper tempering heat treatment.
Description
Technical field
The invention belongs to ferrous materials Field of Heat-treatment, particularly the thermal treatment process of a kind of thick and large section low-carbon low-alloy steel (as: Cr-Mo steel etc.) forge piece.
Background technology
Low-carbon and low-alloy Cr-Mo steel is owing to having better obdurability and excellent anti-hydrogen embrittlement performance, widespread use and large-scale hydrogenator, and nuclear power cylinder body and some have certain requirements on parts to the strength of materials, low-temperature flexibility and resistance to elevated temperatures.Under traditional industry application conditions, the standard thermal treatment technique of low-carbon and low-alloy Cr-Mo steel forge piece is quenching+tempering.After quenching, obtain lower bainite or martensitic stucture, then carry out after the temper of proper temperature, the intensity of material and plasticity and toughness can reach matched well.
But along with the continuous expansion of hydrogenation unit scale and the continuous increase of nuclear power power, size and the wall thickness of low-carbon and low-alloy Cr-Mo steel forge piece significantly increase, quench cooled scarce capacity in Practical manufacturing heat treatment process, although adopted the type of cooling that sprays water with high pressure to improve quench cooling rate when some heavy froging is quenched, but its heart portion is still difficult to through hardening, easily cause that forging gross distortion even ftractures simultaneously.Therefore, it is main middle temperature transformation product that thick and large section (referring generally to section thickness is 100～600mm) low-carbon and low-alloy CrMo steel forge piece heart portion after quenching easily obtains take the poor granular bainite of toughness, has had a strong impact on the low-temperature impact toughness of large-scale workpiece heart portion.
In order to improve the heart portion performance of thick and large section low-carbon and low-alloy CrMo steel forge piece, also there are some bibliographical informations, adopt sub-temperature critical heat treatment process to improve the low-temperature impact toughness of material, due to sub-critical temperature austenitizing, make in tissue higher containing undissolved ferrite content, not only greatly reduce the intensity of material, and significantly reduced the high temperature endurance performance of material, for the part forge piece that material at high temperature performance is had to particular requirement, be not suitable for using.
Therefore, how by brief heat treating technique, under the condition that does not rely on cooling rate, to realize the good combination of thick and large section low-alloy CrMo steel and other low-carbon and low-alloy steel core portion's intensity and plasticity and toughness, significant for the manufacturing of thick and large section low-alloy CrMo steel and other low-carbon low-alloy steel forge pieces.
Summary of the invention
The object of the present invention is to provide a kind of thermal treatment process of thick and large section low-carbon low-alloy steel forge piece, do not increasing or increasing on a small quantity under the prerequisite of production cost as far as possible, do not change casting, forging alloying constituent, only by improving thermal treatment process, adjust each phase character in material structure, regulate total amount, size and the distribution of each phase, improve thick and large section low-carbon low-alloy steel (as: Cr-Mo steel etc.) forge piece core structure, and then the intensity of heavy casting and forging and plasticity and toughness are all effectively improved.
Technical scheme of the present invention is:
A thermal treatment process for thick and large section low-carbon low-alloy steel forge piece, this technique comprises the following steps:
(1) thick and large section low-carbon low-alloy steel forge piece is carried out to quench treatment within the scope of 40 ℃～100 ℃ more than Ac3, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 0.5～1 hour;
(2) after having quenched, carry out the anneal of the following 50 ℃～90 ℃ of temperature of Ac1, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 0.5～2 hour, cooling with air cooling or the cold mode of stove after insulation finishes;
(3) after having annealed, carry out the intermediate heat treatment in ℃ temperature range of Ac3 ± 25, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 0.5～1 hour;
(4) after intermediate heat treatment, carry out the temper in following 60 ℃～110 ℃ temperature ranges of Ac1, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 1～2 hour.
The thermal treatment process of described thick and large section low-carbon low-alloy steel forge piece, step 1) quenching heat treatment, step 3) intermediate heat treatment and step 4) tempering heat treatment, after insulation finishes, do not causing under workpiece cracking or gross distortion condition, adopting speed of cooling to be as quickly as possible cooled to room temperature.
The thermal treatment process of described thick and large section low-carbon low-alloy steel forge piece, step 3) intermediate heat treatment, austenitizing temperature will be controlled in ℃ temperature range of Ac3 ± 25, and when at the following austenitizing of Ac3, undissolved ferrite content should be controlled in 10wt%.
The thermal treatment process of described thick and large section low-carbon low-alloy steel forge piece, step 4) tempering heat treatment adopting, fully take into account M-A island and decompose the obdurability impact of situation on material, avoids separating out the thick carbide distributing along crystal boundary.
The thermal treatment process of described thick and large section low-carbon low-alloy steel forge piece, low-carbon low-alloy steel is that the Cr-Mo that alloying element content is no more than 5wt.% is steel; Or low-carbon low-alloy steel is the low-alloy bainite steel that alloying element content is no more than 5wt.%: NiCr system, MnMoNi system, SiMn system, SiMnMo system, CrMnSi system, CrMnMo system or CrNiMo system.By weight percentage, low-carbon low-alloy steel alloying element mainly comprises: more than one of C≤0.30%, Mn≤1.5%, Cr≤4%, Mo≤1.5%, V≤0.5% and trace alloying element Nb, Ti, B, the massfraction summation of alloying element is no more than 5%.
The thermal treatment process of described thick and large section low-carbon low-alloy steel forge piece, the wall thickness of thick and large section low-carbon low-alloy steel forge piece is at 100～600mm.
Design philosophy of the present invention and principle are as follows:
The present invention improves thick and large section low-carbon low-alloy steel (as: CrMo steel etc.) forge piece heart portion performance by changing cooling rate thinking from existing technique has remarkable different.Main thought of the present invention is not change under the condition of cooling rate, between conventional modulated heat-treatment quenching and tempering heat treatment, by adding intermediate treatment, change granular bainite in continuous cooling kinetic transformation, control the formability of thick and large section low-carbon low-alloy steel (as: CrMo steel etc.) forge piece heart portion granular bainite, the character on the martensite/austenite island in granular bainite (M-A island) particularly, total amount, pattern, size, distribution, and control granular bainite matrix and island in the evolution of drawing process by follow-up suitable adjustment tempering heat treatment system, thereby reach the tough matching optimization object to low-carbon and low-alloy nodular bainite steel.Finally, make to adopt heat treatment condition of the present invention to obtain than prior heat treatment process and there is better obdurability coupling.Concrete principle is as follows:
1, the intermediate heat treatment in the Ac3 ± 25 ℃ temperature range that the present invention adopts, require austenitizing undissolved ferrite content to be controlled in 10wt%, after insulation, with certain speed of cooling, be cooled to room temperature, object is to make the microstructure of material that certain change occur.Specifically, by intermediate heat treatment, changed the continuous cooling transformation (having changed the position of CCT curve) of low-carbon low-alloy steel (as: Cr-Mo steel etc.), particularly granular bainite transition kinetics has been produced to significantly impact.Intermediate heat treatment causes CCT curve to move to left, reduced the formability of granular bainite, make phase transformation at higher temperature, with speed more slowly, carry out, in the tissue of granular bainite ZhongM-A island, rich carbon degree reduces, M-A island and matrix relative hardness is poor reduces, total amount and the size on M-A island are all necessarily reduced simultaneously, and it is more even to distribute.Thereby can realize not reducing the strength of materials or slightly falling under low intensive condition, increase substantially the impelling strength of material, can be good at optimizing the obdurability of material.
2, simultaneously, the present invention adds the thermal treatment of annealing together before intermediate heat treatment, main purpose is to eliminate to using the impact on structural transformation of rate of heating that nonequilibrium state tissue (quenching structure) may bring as intermediate heat treatment original structure, and can avoid heavy casting and forging distortion in intermediate heat treatment process, cracking and Structure Inheritance.
3, the present invention has designed tempering process after intermediate heat treatment, not only can eliminate the unrelieved stress that material produces when quenching, and can in the evolution of drawing process and bainite matrix softening, play an important role to granular bainite microstructure ZhongM-A island, and then the problem that respectively matches in better optimizing tissue, finally make material there is good comprehensive mechanical property.
The technical superiority of the present invention and the contrast of existing technique:
Based on above-mentioned principle, can find out, compared with prior art there is following advantage in technique of the present invention: the intermediate heat treatment in (1) the present invention is mainly to reach by regulating granular bainite two to match the comprehensive mechanical property that improves material, and traditional critical zone thermal treatment austenitizing temperature relatively low (generally more than Ac1 between 30～50 ℃), mainly to utilize amount and the distribution of controlling undissolved ferrite, form is optimized the mechanical property of material, therefore adopt critical zone thermal treatment by sacrificing some strength, to improve often the impelling strength of material, can not meet low-carbon low-alloy steel (as: the CrMo steel etc.) requirement of forge piece to heat resistance.(2) material of the present invention before intermediate heat treatment is equilibrium state tissue, is conducive to after intermediate heat treatment, obtain organizing more uniformly; And general critical zone thermal treatment is to make an addition between quenching-and-tempering process, the nonequilibrium state tissue (quenching structure and quenching are without abundant tempered structure) of usining is processed as critical heat, during this thermal treatment process, easily make workpiece (especially for heavy casting and forging) distortion, cracking, simultaneously nonequilibrium state is organized heating again to inherit to heat for the first time formed thick tissue, material becomes complicated in heat-processed structural transformation, for heavy casting and forging, due to the inequality of rate of heating, may cause the unstable of performance.
Advantage of the present invention and beneficial effect are as follows:
1, the present invention is not changing under the chemical composition condition of low-carbon low-alloy steel for large pressurized vessel (as: Cr-Mo steel etc.), only by the optimization of Heat Treatment Process to material, adjust the character of each phase in Fine Texture of Material, regulate total amount, size and the distribution of each phase, and pass through to optimize tempering process evolution in follow-up drawing process to each, and then improve the obdurability coupling of such steel.
2, the present invention is applied widely, not being only applicable to all large pressurized vessels that are applied to is steel with low-carbon and low-alloy Cr-Mo, also can be no more than for alloying element content the low-carbon and low-alloy bainitic steels such as NiCr system, MnMoNi system, SiMn system, SiMnMo system, CrMnSi system, CrMnMo system or CrNiMo system of 5wt.%, conventional alloy designations can for but be not limited to 2.25Cr1Mo-0.25V, G18CrMo2-6, SA508-3,15CrMoVA, 18Cr
2ni
4wA, 12CrNi3,35SiMnMo, 15SiMnVTi or 25SiMoVB etc.
Accompanying drawing explanation
Fig. 1 is thermal treatment process schematic diagram of the present invention.
Fig. 2 is prior heat treatment process schematic diagram.
Embodiment
In order to improve thick and large section low-carbon low-alloy steel (as: Cr-Mo steel etc.) forge piece heart portion obdurability coupling, the present invention proposes and after the quenching technology of traditional quenching+tempering (being modified thermal treatment), increase by one anneal and intermediate heat treatment, suitably adjust the temperature of tempering heat treatment simultaneously, thereby reach under the limited prerequisite of cooling power, the content, size and the distribution that by changing, in granular bainite microstructure, respectively form phase make material obtain the scheme of desirable obdurability coupling.Concrete implementation step is as follows:
(1) first use dilatometry measure to intend Ac1 and the Ac3 point temperature of the forge piece material of heat-treating, to formulate subsequent heat treatment temperature range;
(2) thick and large section low-carbon low-alloy steel (as: CrMo steel etc.) forge piece is carried out to quench treatment more than Ac3 within the scope of 40 ℃～100 ℃, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 0.5～1 hour; After insulation finishes, do not causing that under workpiece cracking or gross distortion condition, employing speed of cooling is as quickly as possible cooled to room temperature;
(3) after having quenched, carry out the anneal of the following 50 ℃～90 ℃ of temperature of Ac1, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 0.5～2 hour, after insulation finishes, with air cooling or the cold mode of stove, is cooled to room temperature;
(4) after having annealed, carry out the intermediate heat treatment in ℃ temperature range of Ac3 ± 25, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 0.5～1 hour; After insulation finishes, do not causing that under workpiece cracking or gross distortion condition, employing speed of cooling is as quickly as possible cooled to room temperature;
(5) after intermediate heat treatment, carry out the temper in following 60 ℃～110 ℃ temperature ranges of Ac1, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 1～2 hour; After insulation finishes, do not causing that under workpiece cracking or gross distortion condition, employing speed of cooling is as quickly as possible cooled to room temperature.
In the present invention, described " the every increase of wall thickness 25mm holding time is pressed in insulation ", its implication is:
In order well to embody thermal treatment process of the present invention, significantly improve thick and large section low-carbon low-alloy steel (as: CrMo steel etc.) forge piece heart portion obdurability matching effect.In follow-up specific embodiment, the prior heat treatment process that the present invention enumerates, is used for illustrating superiority of the present invention, but prior heat treatment process do not mean that and be subject to the present invention to protect restriction.
For proved invention has wider range of application, and the feasibility of considering actually operating, the present invention selects respectively a kind of typical thick and large section low-carbon and low-alloy CrMo steel forgings (hydrogenator 2.25Cr1Mo0.25V steel thick plate) and a kind of typical thick and large section low-carbon and low-alloy CrMo steel casting (nuclear power low pressure G18CrMo2-6 steel cylinder body) as case study on implementation.Meanwhile, it is low-carbon and low-alloy steel forgings that the present invention also can be used for MnMoNi, and the nuclear power SA508-3 steel thick and large section pressurized vessel of take in an embodiment describes as example.
Embodiment 1
In the present embodiment, 2.25Cr-1Mo-0.25V steel thick plate thermal treatment for large-scale hydrogenator, detailed process is as follows:
(1) first to slab, chemical composition analysis is carried out in sampling, test result is 0.15C (weight percent, 0.05Si, 2.46Cr, 1.01Mo, 0.28V, 0.15Ni, 0.006P, 0.002S, Fe surplus down together),, result meets relevant criterion to the requirement of 2.25Cr-1Mo-0.25V steel chemical composition, and belongs to the scope of application of the present invention.On rolling slab, get the pole of φ 3x10mm, the Ac3, the Ac1 that use methods of thermal expansion to record material are respectively 886 ℃, 776 ℃.
(2) forging after postheat treatment, is the slab that 400mm is thick to wall thickness, carries out the austenitizing of 980 ℃ * 8h and processes, and then carries out spray quenching processing;
(3) after having quenched, slab is done to anneal at 725 ℃, annealing soaking time is 16 hours, adopts air cooling mode to be cooled to room temperature;
(4) after anneal, slab is done respectively to the intermediate heat treatment (technique one, technique two austenitizing temperatures are respectively 905 ℃, 870 ℃) of the present embodiment technique, thermal treatment soaking time is 8h, and after coming out of the stove, water spray is cooled to room temperature.
(5) thermal treatment process schematic diagram of the present invention as shown in Figure 1.The suitable tempering heat treatment of coupon difference of step (4), the technique one of the present embodiment, technique two tempering temperatures are respectively 690 ℃ and 670 ℃, and thermal treatment soaking time is 16h, and after coming out of the stove, water spray is cooled to room temperature.
(6) prior heat treatment process schematic diagram as shown in Figure 2.In order to process contrast with the present embodiment thermal treatment process, an other same material, unidimensional 2.25Cr1Mo0.25V steel thick plate, use prior heat treatment process to process, concrete thermal treatment process is 940 ℃ * 8h quench treatment+700 ℃ * 16h temper, quench and the tempering type of cooling be spray water cooling.
(7) from prior heat treatment process, Optimization Technology one and Optimization Technology two, the test block that same size is got in slab centre after three kinds of art breading, be processed into tension specimen and summer than V-type impact specimen, test respectively normal, drawing by high temperature mechanical property, and low temperature impact properties, test result is as shown in table 1.From experimental results, the present embodiment adopting process one is all better than prior heat treatment process with technique two.
In table 1: embodiment 1,2.25Cr-1Mo-0.25V steel thick plate adopts the present embodiment process optimization and the contrast of traditional technology mechanical property
(8) table 2 has provided use the present embodiment art breading and traditional technology processing 2.25Cr1Mo0.25V steel thick plate centre microstructure feature, contrast can be found out, use after the present embodiment art breading, granular bainite Zhong M-A island quantity and size all decline to some extent than traditional technology, M-A island is distributed in intracrystalline more simultaneously, and hardness declines to some extent.The variation of these parameters of M-A island meets the principle of design of the present embodiment, is the reason that material impact toughness improves.
Microstructure characteristic after 2.25Cr-1Mo-0.25V steel thick plate employing the present embodiment technique and traditional technology thermal treatment in table 2: embodiment 1
Embodiment 2
In the present embodiment, nuclear power is processed by G18CrMo2-6 steel low pressure (LP) cylinder body heat, and detailed process is as follows:
(1) the present embodiment is massive casting, and material is G18CrMo2-6 steel, and thickest 500mm is thick.First detecting the present embodiment material main chemical compositions is 0.15C, 0.61Cr, 0.61Mo, 0.75Mn, 0.75Mn, 0.46Ni, Fe surplus, meets the scope of application of the present invention.Utilize transformation temperature Ac1, the Ac3 of the material of thermal expansion survey to be respectively: 760 ℃, 880 ℃.
(2) identical with embodiment 1, first the present embodiment also quenches to foundry goods and the thermal treatment of annealing, but is with embodiment 1 difference, and the present embodiment quenching austenitizing temperature is 920 ℃, is incubated 20 hours, and blowing is chilled to room temperature; Annealing temperature is 670 ℃, insulation 40h, and the cold mode of stove is cooled to room temperature.
(3) after anneal, the present embodiment carries out intermediate heat treatment to relevant foundry goods, and treatment temp adopts two kinds of differing tempss, that is: one, 890 ℃ of normalizing of technique; Two, 855 ℃ of normalizings of technique).Soaking time is 15h, and after insulation finishes, blowing is chilled to room temperature.
(4) after normalizing treatment, the present embodiment carries out temper to relevant foundry goods, and the tempering temperature of technique one is 700 ℃, and the tempering temperature of technique two is 650 ℃.Soaking time is 30h, and after insulation finishes, blowing is chilled to room temperature.
(5) in order to process contrast with the present embodiment thermal treatment process, to identical material, the foundry goods of same size, carries out prior heat treatment process processing (920 ℃ * 20h normalizing treatment, blowing is chilled to room temperature+680 ℃ * 30h temper, and blowing is chilled to room temperature).
(6) from prior heat treatment process, Optimization Technology one and Optimization Technology two, the test block that same size is got in centre, foundry goods thickest place after three kinds of art breading, be processed into tension specimen and summer than V-type impact specimen, test respectively normal, drawing by high temperature mechanical property, and low temperature impact properties, test result is as shown in table 3.From experimental results, the present embodiment adopting process one is all better than prior heat treatment process with technique two.
Table 3:G18CrMo2-6 steel adopts the present embodiment process optimization and the contrast of traditional technology mechanical property
Embodiment 3
In the present embodiment, large pressurized vessel steel thermal treatment for nuclear power, detailed process is as follows:
(1) the present embodiment is heavy froging, and material is the Mn-Mo-Ni steel of the SA508-3 trade mark, and maximum heavy wall is 350mm.The main chemical compositions of test material is 0.23C, 0.18Cr, 0.48Mo, 1.48Mn, 0.75Mn, 0.8Ni, 0.22Si, Fe surplus, wherein impurity element scope control, in the scope of standard regulation, utilizes transformation temperature Ac1, the Ac3 of the material of thermal expansion survey to be respectively: 714 ℃, 809 ℃.
(2) identical with embodiment 1, first the present embodiment also quenches to foundry goods and the thermal treatment of annealing, but is with embodiment 1 difference, and the present embodiment quenching austenitizing temperature is 860 ℃, is incubated 12 hours, and oil quenching is to room temperature; Annealing temperature is 660 ℃, insulation 24h, and the cold mode of stove is cooled to room temperature.
(3) after anneal, the present embodiment carries out intermediate heat treatment to relevant heavy froging, and treatment temp adopts two kinds of differing tempss, that is: one, 815 ℃ of normalizing of technique; Two, 795 ℃ of normalizings of technique.Soaking time is 15h, and after insulation finishes, air cooling is to room temperature.
(4) after intermediate heat treatment, the present embodiment carries out temper to relevant forging, and the tempering temperature of technique one is 650 ℃, and the tempering temperature of technique two is 640 ℃.Soaking time is 30h, and after insulation finishes, air cooling is to room temperature.
(5) in order to process contrast with the present embodiment thermal treatment process, to identical material, the forging of same size, carry out prior heat treatment process processing (860 ℃ * 15h normalizing treatment, air cooling to room temperature+660 ℃ * 28h temper, air cooling is to room temperature).
(6) from prior heat treatment process, Optimization Technology one and Optimization Technology two, the test block that same size is got in centre, foundry goods thickest place after three kinds of art breading, be processed into tension specimen and summer than V-type impact specimen, test respectively tensile mechanical properties, and low temperature impact properties, test result is as shown in table 4.From experimental results, the present embodiment adopting process one is all better than prior heat treatment process with technique two.
Table 4:SA508-3 steel adopts the present embodiment process optimization and the contrast of traditional technology mechanical property
Embodiment result shows, the present invention is in traditional quenching, between tempering heat treatment, add the anneal of the following 50 ℃～90 ℃ of temperature of an Ac1 and the intermediate heat treatment in an Ac3 ± 25 ℃ temperature range, correspondingly adjust the tempering temperature of traditional technology simultaneously, thereby reach by intermediate heat treatment and regulate the content of (being called for short M-A island) of martensite/austenite island structure in thick and large section heart portion granular bainite microstructure, size, carbon concentration, the object of hardness and distributing position, realize the matched well with matrix, further by suitable tempering heat treatment, controlling granular bainite matrix HeM-A island makes thick and large section steel forge piece core structure have good obdurability in the evolution of drawing process.Thereby in the time of can solving large section low-carbon low-alloy steel forge piece because of the large thermal treatment of wall thickness, heart portion quenches and thoroughly to produce the low and unsettled problem of low-temperature impact toughness.
Claims (7)
1. a thermal treatment process for thick and large section low-carbon low-alloy steel forge piece, is characterized in that, this technique comprises the following steps:
(1) thick and large section low-carbon low-alloy steel forge piece is carried out to quench treatment within the scope of 40 ℃～100 ℃ more than Ac3, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 0.5～1 hour;
(2) after having quenched, carry out the anneal of the following 50 ℃～90 ℃ of temperature of Ac1, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 0.5～2 hour, cooling with air cooling or the cold mode of stove after insulation finishes;
(3) after having annealed, carry out the intermediate heat treatment in ℃ temperature range of Ac3 ± 25, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 0.5～1 hour;
(4) after intermediate heat treatment, carry out the temper in following 60 ℃～110 ℃ temperature ranges of Ac1, insulation is pressed the every increase of wall thickness 25mm holding time and is calculated for 1～2 hour.
2. by the thermal treatment process of thick and large section low-carbon low-alloy steel forge piece claimed in claim 1, it is characterized in that: step 1) quenching heat treatment, step 3) intermediate heat treatment and step 4) tempering heat treatment, after insulation finishes, do not causing under workpiece cracking or gross distortion condition, adopting speed of cooling to be as quickly as possible cooled to room temperature.
3. by the thermal treatment process of thick and large section low-carbon low-alloy steel forge piece claimed in claim 1, it is characterized in that: step 3) intermediate heat treatment, austenitizing temperature will be controlled in ℃ temperature range of Ac3 ± 25, and when at the following austenitizing of Ac3, undissolved ferrite content should be controlled in 10wt%.
4. by the thermal treatment process of thick and large section low-carbon low-alloy steel forge piece claimed in claim 1, it is characterized in that: step 4) tempering heat treatment that adopts, fully take into account M-A island and decompose the obdurability impact of situation on material, avoid separating out the thick carbide distributing along crystal boundary.
5. by the thermal treatment process of thick and large section low-carbon low-alloy steel forge piece claimed in claim 1, it is characterized in that, low-carbon low-alloy steel is that the Cr-Mo that alloying element content is no more than 5wt.% is steel; Or low-carbon low-alloy steel is the low-alloy bainite steel that alloying element content is no more than 5wt.%: NiCr system, MnMoNi system, SiMn system, SiMnMo system, CrMnSi system, CrMnMo system or CrNiMo system.
6. by the thermal treatment process of thick and large section low-carbon low-alloy steel forge piece claimed in claim 5, it is characterized in that, by weight percentage, low-carbon low-alloy steel alloying element mainly comprises: more than one of C≤0.30%, Mn≤1.5%, Cr≤4%, Mo≤1.5%, V≤0.5% and trace alloying element Nb, Ti, B, the massfraction summation of alloying element is no more than 5%.
7. by the thermal treatment process of thick and large section low-carbon low-alloy steel forge piece claimed in claim 1, it is characterized in that: the wall thickness of thick and large section low-carbon low-alloy steel forge piece is at 100～600mm.
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| CN109837367A (en) * | 2017-11-28 | 2019-06-04 | 中国科学院金属研究所 | Refine the heat treatment process on the island M-A in low-carbon low-alloy steel granular bainite microstructure |
| CN114517253A (en) * | 2020-11-20 | 2022-05-20 | 中国科学院金属研究所 | Hot working process for eliminating blocky structure in low-alloy steel large forging |
| CN114807544A (en) * | 2022-04-07 | 2022-07-29 | 扬州大学 | Double-temperature double-time combined heat treatment method for high-wear-resistance CrMnMoN alloy |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS609825A (en) * | 1983-06-27 | 1985-01-18 | Sumitomo Metal Ind Ltd | Production of tough and hard steel |
| JPS6289809A (en) * | 1985-04-25 | 1987-04-24 | Kawasaki Steel Corp | Manufacture of steel for pressure vessel having superior resistance to hydrogen induced cracking |
| CN101654728A (en) * | 2009-09-25 | 2010-02-24 | 清华大学 | Method for preparing manganese chilled bainitic steel |
| CN101713054A (en) * | 2009-12-28 | 2010-05-26 | 舞阳钢铁有限责任公司 | Large thickness steel plate for hydrogenation reaction chamber reeling equipment and production method thereof |
| CN102080187A (en) * | 2010-12-21 | 2011-06-01 | 南阳汉冶特钢有限公司 | Large-thickness Cr-Mo system 12Cr2Mo1R container steel and production method thereof |
-
2014
- 2014-06-19 CN CN201410273812.3A patent/CN104164548B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS609825A (en) * | 1983-06-27 | 1985-01-18 | Sumitomo Metal Ind Ltd | Production of tough and hard steel |
| JPS6289809A (en) * | 1985-04-25 | 1987-04-24 | Kawasaki Steel Corp | Manufacture of steel for pressure vessel having superior resistance to hydrogen induced cracking |
| CN101654728A (en) * | 2009-09-25 | 2010-02-24 | 清华大学 | Method for preparing manganese chilled bainitic steel |
| CN101713054A (en) * | 2009-12-28 | 2010-05-26 | 舞阳钢铁有限责任公司 | Large thickness steel plate for hydrogenation reaction chamber reeling equipment and production method thereof |
| CN102080187A (en) * | 2010-12-21 | 2011-06-01 | 南阳汉冶特钢有限公司 | Large-thickness Cr-Mo system 12Cr2Mo1R container steel and production method thereof |
Non-Patent Citations (3)
| Title |
|---|
| 刘同湖等: "加氢反应器特厚锻件的热处理", 《大型铸锻件》 * |
| 叶文邦等: "《压力容器设计指导手册 上册 》", 31 August 2006, 云南科学技术出版社 * |
| 张文辉等: "加氢反应器用2.25Cr-1Mo钢锻件的热处理", 《大型铸锻件》 * |
Cited By (8)
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|---|---|---|---|---|
| CN109837367A (en) * | 2017-11-28 | 2019-06-04 | 中国科学院金属研究所 | Refine the heat treatment process on the island M-A in low-carbon low-alloy steel granular bainite microstructure |
| CN109837367B (en) * | 2017-11-28 | 2020-09-18 | 中国科学院金属研究所 | Heat treatment process for refining M-A island in granular bainite structure of low-carbon low-alloy steel |
| CN109158460A (en) * | 2018-08-22 | 2019-01-08 | 中国原子能科学研究院 | A kind of manufacturing method of bellows |
| CN114517253A (en) * | 2020-11-20 | 2022-05-20 | 中国科学院金属研究所 | Hot working process for eliminating blocky structure in low-alloy steel large forging |
| CN115216605A (en) * | 2021-04-16 | 2022-10-21 | 中国科学院金属研究所 | Method for eliminating black spot tissue in large-scale low-alloy steel forging |
| CN115216605B (en) * | 2021-04-16 | 2024-01-19 | 中国科学院金属研究所 | Method for eliminating black spot tissue in large low-alloy steel forging |
| CN114807544A (en) * | 2022-04-07 | 2022-07-29 | 扬州大学 | Double-temperature double-time combined heat treatment method for high-wear-resistance CrMnMoN alloy |
| CN114807544B (en) * | 2022-04-07 | 2023-09-08 | 扬州大学 | Double-temperature double-time combined heat treatment method for high-wear-resistance CrMnMoN alloy |
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