CN108890224A - A method of improving Q345E ring low-temperature impact toughness - Google Patents
A method of improving Q345E ring low-temperature impact toughness Download PDFInfo
- Publication number
- CN108890224A CN108890224A CN201810694336.0A CN201810694336A CN108890224A CN 108890224 A CN108890224 A CN 108890224A CN 201810694336 A CN201810694336 A CN 201810694336A CN 108890224 A CN108890224 A CN 108890224A
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- China
- Prior art keywords
- ring
- upset
- impact toughness
- low
- temperature impact
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
- B21J5/002—Hybrid process, e.g. forging following casting
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/40—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rings; for bearing races
Abstract
The invention discloses a kind of methods for improving Q345E ring low-temperature impact toughness, belong to technical field of metal material.This method is successively to carry out upset, punching for Q345E continuous cast round billets, roll over ring and heat treatment, to improve the low-temperature impact toughness of gained Q345E ring；Wherein, strict control Q345E carbon equivalent ce V, and increase using reaming after the upset plate of taper is upset and punching the forging ratio of manufacturing process；It is cooled down after being warming up to 910 DEG C ± 10 DEG C and heat preservation and heat preservation by power after being warming up to 650 DEG C ± 10 DEG C using room temperature shove charge, by power and keeping the temperature 1 hour and makes cooling velocity >=0.5 DEG C/s；After being processed using the method for the present invention, banded structure inside ring, refinement crystal grain are eliminated, the low-temperature impact toughness of ring is greatly improved, part by one-step qualification rate is greater than 95%.
Description
Technical field
The present invention relates to technical field of metal material, and in particular to a kind of side for improving Q345E ring low-temperature impact toughness
Method.
Background technique
Q345E has good intensity, toughness and low temperature impact properties, is widely used as low-alloy structural steel
Stringent field is required solderability and low-temperature impact toughness in wind-powered electricity generation, ship, aerospace etc., according to most stringent of standard,
It is required that low-temperature impact toughness (- 50 DEG C)：Impact of collision function >=50J, side knock function >=34J.Therefore, it is necessary to by Q345E
Ring process optimizes, to improve its low-temperature impact toughness, to meet the requirement under limiting condition.
Summary of the invention
The purpose of the present invention is to provide a kind of methods for improving Q345E ring low-temperature impact toughness, pass through strict control
Carbon equivalent ce V, increase forging ratio, heating heat treatment process appropriate and accelerate cooling velocity after being heat-treated and rushed to improve low temperature
Hit toughness.
To achieve the above object, the technical solution adopted in the present invention is as follows：
A method of improve Q345E ring low-temperature impact toughness, this method be for Q345E continuous cast round billets, successively into
Row is upset, punching, rolles over ring and heat treatment, to improve the low-temperature impact toughness of gained Q345E ring；This method specifically include as
Lower step：
(1) upset processing：Continuous cast round billets are carried out using taper upset plate upset；The upset ratio of the continuous cast round billets is greater than
1.7；It is described it is upset than refer to the upset preceding cutting length of continuous cast round billets and it is upset after height ratio；
(2) punching is handled：Upset treated that ring blank is punched out, and obtains ring blank through reaming again after punching
Interim size；Piercing process middle section ratio is greater than 1.0；The section than refer to after punching with the ring section after reaming
The ratio between product；
(3) ring processing is rolled over：Ring blank after expanding treatment carries out rolling ring, the blank ring of specification needed for obtaining；Roll over ring
Rolling than being greater than 2.3 in processing, it is described roll than refer to after reaming with roll over the ratio between ring sectional area after ring；
(4) it is heat-treated：After blank ring shove charge after rolling over ring, first it is warming up to 640-660 DEG C and keeps the temperature 1 hour, then heat up
To 900-920 DEG C and held for some time, ring is taken out after heat preservation, and 600 DEG C or less are cooled to outside furnace.The Q345E continuous casting
Carbon equivalent ce V≤0.45 of round billet.
In above-mentioned steps (1), the upset plate of taper includes the Upper cylindrical being connected and lower part rotary table, cylinder and rotary table
Upper bottom surface be connected (upper bottom surface diameter be greater than bottom surface diameter)；The diameter of section of cylinder is greater than the upper bottom surface diameter of rotary table；
The angle of rotary table bus and axis is 20-30 °.
In above-mentioned steps (2), the requirement of the punching hole diameter d in punching is：50%≤d of blank diameter≤blank diameter
55%, to prevent blank from deflection deformation occur；It is too big that subsequent reaming process deflection is avoided result in simultaneously, and influences deformation matter
Amount and production efficiency；Reach the inner hole size of interim size by expanding treatment.
In above-mentioned steps (4), forging is room temperature when ring shove charge and furnace temperature is not higher than 300 DEG C；Multiple rings exist when shove charge
It is placed in furnace according to way of stacking, the way of stacking refers to, each ring stacks placement in the vertical direction and forms a line, total N
Column；The distance between each column≤3 meters, N >=3 are separated between two neighboring ring using multiple equal-height padding irons in each column, and parallels is high
Degree is greater than 50mm, and the spacing between each parallels placed in each plane is less than 1500mm.
In above-mentioned steps (4), when ring is in 900-920 DEG C of heat preservation, soaking time is calculated by ring effective thickness,
Its effective thickness is the minimum value for taking wall thickness and height, soaking time=effective thickness × 1.2min/mm.
In above-mentioned steps (4), when ring is cooling, cooling velocity >=0.5 DEG C/s；The watering of cooled region ground, water surface elevation
For 2~3mm.Preferably cooling condition is：When room temperature≤15 DEG C, effective thickness≤150mm, ring cooling need to be in outdoor dispersion
Cooling, cooling velocity is 0.5 DEG C/s；When room temperature≤15 DEG C, effective thickness >=150mm, ring cooling needs air blast cooling, makes
Cooling velocity >=0.5 DEG C/s；When 15 DEG C of room temperature >, ring cooling needs air blast cooling, makes cooling velocity >=0.5 DEG C/s.
The Q345E ring is after processing, in -50 DEG C of low-temperature impact toughness：Impact of collision function >=50J, laterally punching
Hit function >=34J；Time processing part qualification rate is greater than 95%.
Advantages of the present invention and benefit are：
1, it after Q345E ring is using the method for the present invention processing, eliminates internal banded structure, refinement crystal grain, improve ingredient
Segregation improves internal content of pearlite in alloy and eliminates internal stress, make low-temperature impact toughness reach -50 DEG C, impact of collision function >=
50J, side knock function >=34J.
2, using the method for the present invention, percent defective will be caused to be reduced in product by 30% since low-temperature impact toughness is relatively low
To 5%, hence it is evident that improve the qualification rate of product.Not only meet the product quality of customer requirement, but also saves manufacture product cost
15% or so, improve Enterprise Integrated competitiveness.
Detailed description of the invention
Fig. 1 is tapered upset hardened structure used in the method for the present invention.
Fig. 2 is heat treatment cycle curve of the present invention.
Fig. 3 is normative heat treatment process curve.
Fig. 4 is the metallographic structure figure obtained using process of the invention and ballistic work numerical value.
Fig. 5 is the metallographic structure figure obtained using conventional process and ballistic work numerical value.
Specific embodiment
The present invention is described in detail with reference to the accompanying drawings and examples.
Using Q345E continuous cast round billets as original blank in following embodiment, carbon equivalent ce V≤0.45；The taper pier used
Structure snd size such as Fig. 1 of thick plate.The upset plate of taper includes the Upper cylindrical being connected and lower part rotary table, cylinder and rotary table it is upper
Bottom surface is connected (upper bottom surface diameter is greater than bottom surface diameter)；The diameter of section of cylinder is greater than the upper bottom surface diameter of rotary table；Rotary table
The angle of bus and axis is 20-30 °.
Embodiment 1：
The method that the present embodiment improves Q345E ring low-temperature impact toughness is specific as follows：
(1) upset processing：Continuous cast round billets are carried out using taper upset plate upset；The upset ratio of the continuous cast round billets is greater than
1.7；It is described it is upset than refer to the upset preceding cutting length of continuous cast round billets and it is upset after height ratio；
(2) punching is handled：Upset treated that ring blank is punched out, and obtains ring blank through reaming again after punching
Interim size；The section ratio is greater than 1.0；The section than refer to after punching with the ratio between the ring sectional area after reaming；Its
In：The requirement of punching hole diameter d is：50%≤d of blank diameter≤round billet diameter 55%, to prevent blank from bending deformation occur
Shape；It is too big to avoid result in subsequent reaming process deflection simultaneously, and influences texturing quality and production efficiency；Pass through expanding treatment
Reach the inner hole size of interim size.
(3) ring processing is rolled over：Ring blank after expanding treatment carries out rolling ring, the blank ring of specification needed for obtaining；It is described
Roll than being greater than 2.3, it is described roll than refer to after reaming with roll over the ratio between ring sectional area after ring；With the upset plate of taper it is upset and
Reaming increases the forging ratio of manufacturing process after punching, makes forging ratio >=5；The forging ratio refers to above-mentioned (1), (2), (3)
The upset ratio of process, section ratio and roll than the sum of.
(4) it is heat-treated：After ring shove charge after reaming, first it is warming up to 650 DEG C and keeps the temperature 1 hour, then be warming up to 910 DEG C simultaneously
Held for some time, ring is taken out after heat preservation, and 600 DEG C are cooled to outside furnace hereinafter, process curve is as shown in Figure 2.
Forging is room temperature when ring shove charge and furnace temperature is not higher than 300 DEG C；Multiple rings are in furnace according to stacking side when shove charge
Formula is placed, and the way of stacking refers to, each ring stacks placement in the vertical direction and forms a line, totally 3 column；Between each column away from
From≤3 meters, separated between two neighboring ring using 8 equal-height padding irons in each column, parallels height 60mm, is placed in each plane
Each parallels between spacing be less than 1000mm.
When ring is in 900-920 DEG C of heat preservation, soaking time is calculated by ring effective thickness, and effective thickness is to take
The minimum value of wall thickness and height, soaking time=effective thickness × 1.2min/mm.
When ring is cooling, the watering of cooled region ground, water surface elevation 3mm.Room temperature≤15 DEG C when cooling, effective thickness≤
150mm, ring is cooling in outdoor dispersion, and cooling velocity is 0.5 DEG C/s.
Fig. 4 is the ring product metallographic structure figure obtained using the present embodiment, it can be seen that Q345E ring uses this hair
After bright method processing, internal banded structure, refinement crystal grain are eliminated.
After processing, in -50 DEG C of low-temperature impact toughness such as table 1, time processing part qualification rate is big for the Q345E ring
In 95%.
1 embodiment of table, 1 ring low-temperature impact toughness
Comparative example 1：
With embodiment the difference is that：Using heat treatment cycle curve as shown in Figure 3.
Fig. 5 is the ring product metallographic structure figure obtained using the comparative example, it can be seen that is had inside Q345E ring
Banded structure, coarse grains.
After processing, in -50 DEG C of low-temperature impact toughness such as table 2, time processing part qualification rate is about for the Q345E ring
It is 70%.
2 comparative example of table, 1 ring low-temperature impact toughness
Certainly, above description is not limitation of the present invention, and the present invention is also not limited to above-mentioned narration, the art
The variations, modifications, additions or substitutions that those of ordinary skill is made within the essential scope of the present invention also belong to guarantor of the invention
Protect range.
Claims (9)
1. a kind of method for improving Q345E ring low-temperature impact toughness, it is characterised in that：This method is for Q345E continuous casting circle
Base successively carries out upset, punching, rolles over ring and heat treatment, to improve the low-temperature impact toughness of gained Q345E ring；This method
Specifically comprise the following steps：
(1) upset processing：Continuous cast round billets are carried out using taper upset plate upset；The upset ratio of the continuous cast round billets is greater than 1.7；
It is described it is upset than refer to the upset preceding cutting length of continuous cast round billets and it is upset after height ratio；
(2) punching is handled：Upset treated that ring blank is punched out, and obtains the mistake of ring blank through reaming again after punching
Cross size；Piercing process middle section ratio is greater than 1.0；The section than refer to after punching with the ring sectional area after reaming it
Than；
(3) ring processing is rolled over：Ring blank after expanding treatment carries out rolling ring-rolling, the blank ring of specification needed for obtaining；Roll over ring
Rolling than being greater than 2.3 in processing；It is described roll than refer to after reaming with roll over the ratio between ring sectional area after ring；
(4) it is heat-treated：After blank ring shove charge after rolling over ring, first it is warming up to 640-660 DEG C and keeps the temperature 1 hour, then be warming up to
900-920 DEG C and held for some time, ring is taken out after heat preservation, and 600 DEG C or less are cooled to outside furnace.
2. the method according to claim 1 for improving Q345E ring low-temperature impact toughness, it is characterised in that：The Q345E
Carbon equivalent ce V≤0.45 of continuous cast round billets.
3. the method according to claim 1 for improving Q345E ring low-temperature impact toughness, it is characterised in that：Step (1)
In, the upset plate of taper includes the Upper cylindrical being connected and lower part rotary table, and cylinder is connected with the upper bottom surface of rotary table；Cylinder
Diameter of section be greater than rotary table upper bottom surface diameter；The angle of rotary table bus and axis is 20-30 °.
4. the method according to claim 1 for improving Q345E ring low-temperature impact toughness, it is characterised in that：Step (2)
In, the requirement of the punching hole diameter d in punching is：50%≤d of round billet diameter≤round billet blank diameter 55%, to prevent blank
There is deflection deformation；It is too big to avoid result in subsequent reaming process deflection simultaneously, and influences texturing quality and production efficiency；It is logical
Cross the inner hole size that expanding treatment reaches interim size.
5. the method according to claim 1 for improving Q345E ring low-temperature impact toughness, it is characterised in that：Step (4)
In, forging is room temperature when ring shove charge and furnace temperature is not higher than 300 DEG C；Multiple rings are put in furnace according to way of stacking when shove charge
It sets, the way of stacking refers to, each ring stacks placement in the vertical direction and forms a line, total N column；The distance between each column≤
3 meters, N >=3 are separated between two neighboring ring using multiple equal-height padding irons in each column, and parallels height is greater than 50mm, each plane
Spacing between each parallels of upper placement is less than 1500mm.
6. the method according to claim 1 for improving Q345E ring low-temperature impact toughness, it is characterised in that：Step (4)
In, when ring is in 900-920 DEG C of heat preservation, soaking time is calculated by ring effective thickness, and effective thickness is to take wall thickness
With the minimum value of height, soaking time=effective thickness × 1.2min/mm.
7. the method according to claim 1 for improving Q345E ring low-temperature impact toughness, it is characterised in that：Step (4)
In, when ring is cooling, cooling velocity >=0.5 DEG C/s；The watering of cooled region ground, water surface elevation are 2~3mm.
8. the method according to claim 7 for improving Q345E ring low-temperature impact toughness, it is characterised in that：Step (4)
In, when ring is cooling, when room temperature≤15 DEG C, effective thickness≤150mm, ring cooling need to be cooling in outdoor dispersion, cooling
Speed is 0.5 DEG C/s；When room temperature≤15 DEG C, effective thickness >=150mm, ring cooling need air blast cooling, make cooling velocity >=
0.5℃/s；When 15 DEG C of room temperature >, ring cooling needs air blast cooling, makes cooling velocity >=0.5 DEG C/s.
9. the method for -8 any raising Q345E ring low-temperature impact toughness according to claim 1, it is characterised in that：Institute
It states Q345E ring after processing, is in -50 DEG C of low-temperature impact toughness：Impact of collision function >=50J, side knock function >=34J；
Time processing part qualification rate is greater than 95%.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810694336.0A CN108890224A (en) | 2018-06-29 | 2018-06-29 | A method of improving Q345E ring low-temperature impact toughness |
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| CN201810694336.0A CN108890224A (en) | 2018-06-29 | 2018-06-29 | A method of improving Q345E ring low-temperature impact toughness |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110993040A (en) * | 2019-11-28 | 2020-04-10 | 太原科技大学 | Method for determining critical value of 30Cr2Ni4MoV steel converted from casting state to forging state |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110993040A (en) * | 2019-11-28 | 2020-04-10 | 太原科技大学 | Method for determining critical value of 30Cr2Ni4MoV steel converted from casting state to forging state |
| CN110993040B (en) * | 2019-11-28 | 2023-03-14 | 太原科技大学 | Method for determining critical value of 30Cr2Ni4MoV steel converted from cast state to forged state |
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Application publication date: 20181127 |