CN102605148A - Weathering steel flame straightening process - Google Patents
Weathering steel flame straightening process Download PDFInfo
- Publication number
- CN102605148A CN102605148A CN2012100967468A CN201210096746A CN102605148A CN 102605148 A CN102605148 A CN 102605148A CN 2012100967468 A CN2012100967468 A CN 2012100967468A CN 201210096746 A CN201210096746 A CN 201210096746A CN 102605148 A CN102605148 A CN 102605148A
- Authority
- CN
- China
- Prior art keywords
- workpiece
- flame
- heating
- area
- infrared thermometer
- 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.)
- Pending
Links
Images
Abstract
The invention relates to a weathering steel flame straightening process, belonging to the technical field of metal material processing. The weathering steel flame straightening process comprises the following steps: calibrating the emissivity of an infrared thermometer according to different materials; determining that the test distance ratio is 30:1; heating a workpiece heating area uniformly by using the neutral oxyacetylene flame, and monitoring the center area of the workpiece heating area in real time by using the infrared thermometer; controlling the highest heating temperature of a flame straightening area on the workpiece at 730-750 DEG C, controlling the emissivity of the infrared thermometer at 0.85, keeping the highest heating temperature of the flame straightening area at 730-750 DEG C for 2 to 3 minutes after the highest heating temperature of the flame straightening area reaches 730-750 DEG C, and cooling the workpiece heating area in air. Due to the adoption of the method, the hardness and the strength of the weathering steel flame straightening area can be close to those of the base material, the metal low-temperature impact energy of the weathering steel flame straightening area can be higher than that of the base material, and at the test temperature of 40 DEG C below zero, the impact energy of the weathering steel flame straightening area of which the highest heating temperature is controlled at 600-650 DEG C can be 2.5 times of that of the workpiece made of the same material.
Description
Technical field
The invention belongs to metal material processing Technology field, be specifically related to a kind of weathering steel flame shrinking technology.
Background technology
Flame shrinking is soft steel welded construction a kind of ME commonly used.And weathering steel is the hot rolled plate that the EMU welded bogie is selected for use.Again because of it contains certain alloying constituent, like copper, phosphorus, chromium, nickel etc., make such steel to the susceptibility of flame heating apparently higher than ordinary low-carbon steel.In case Flame Heating Temperature is selected improper or produces to depart from more greatly, will make the mother metal performance in flame heating district produce noticeable change (Fig. 1), seriously reduce the use properties and the safety in operation of bogie frame.Also very careful on high weather resistance steel framework product, adopting the flame shrinking technology both at home and abroad.Can on high weather resistance steel framework product, use the flame shrinking technology well, key be: can first appropriately select and the thermal gauge model of accurately controlling the flame heating district.The present domestic relevant report that also do not have.The selection of Flame Heating Temperature and control are also based on traditional experience in the production.
Summary of the invention
The purpose of this invention is to provide a kind of hardness that makes weathering steel flame shrinking district mother metal and intensity near mother metal, the low-temperature impact work of flame shrinking district metal is higher than mother metal, ballistic work with compare the flame shrinking technology that significantly improves with the material test specimen.
The present invention includes the following step:
1. select to measure TR-32 ℃～1350 ℃, the measuring distance infrared thermometer more adjustable than 30: 1, measuring accuracy ± 1.5%, 0.1 ℃ of resolving power, time of response＜1 second, spectral response 8～14um, emittance 0.10～1.00; To read over specification sheets before using; Grasp principle and method of use, and the emittance of infrared thermometer is carried out actual demarcation according to workpiece flame shrinking district maximum heating temperature difference;
2. confirm measuring distance than satisfying 30: 1, the area of object being measured is greater than 2 times of area of detection of infrared thermometer;
3. be ready to the weathering steel heated parts, and heating location and the shape definite according to the flame shrinking technology of routine, the profile in the flame heating of on workpiece, drawing district, clear and definite heated perimeter;
With neutral oxy-acetylene flame to workpiece heating zone even heating, with infrared thermometer the centre of heating zone is monitored in real time simultaneously; When no follow-up stress-removal thermal treatment, the workpiece heating zone must not be selected in the bigger tensile stress district of load;
5. the flame shrinking district maximum heating temperature on the workpiece will be controlled at 730～750 ℃; The emittance of infrared thermometer is 0.85; After the flame shrinking district maximum heating temperature on the workpiece reaches 730～750 ℃, kept again 2～3 minutes, guarantee that there is the process of an equalizing temperature heating zone;
6. let the heating zone get into as air-cooled condition, make workpiece naturally cool to room temperature;
7. must not be on the workpiece same position heating and cooling process of repeating step 4--6 repeatedly.
Industrial circle adopted tempilstick or thermocouple temperature measurement in the past.Adopt the tempilstick thermometric only can judge a certain boundary value, can not realize continuous temperature measurement and flexible thermometric; Adopt thermocouple temperature measurement then be not suitable for surface temperature measurement with on a large scale to the flexible monitoring thermometric of workpiece surface.Infrared thermometer then is highly suitable for the flexible thermometric of workpiece surface; But must by the corresponding relation (Fig. 2) of workpiece surface temperature that provides of the present invention and emittance to infrared thermometer important program parameters---emittance is carried out actual checking; Promptly when the flame shrinking district maximum heating temperature on the workpiece will be controlled at 730--750 ℃, the emittance of infrared thermometer was 0.85; Otherwise, can influence the accuracy of infrared thermometer.
Flame shrinking technology in the past mostly at 600～700 ℃, promptly can not surpass 727 ℃ of the transformation temperatures of steel to the span of control of heating zone top temperature; Avoid surpassing transformation temperature as far as possible.Flame shrinking technology of the present invention stresses that then flame shrinking district top temperature will be controlled near the TR of AC1, and promptly 730--750 ℃, the decrease of hardness of correcting district's mother metal this moment is minimum, and intensity is basically consistent with mother metal, and low-temperature impact work is very desirable.Its technology intension is exactly through this heating process, reduces the sheet globular cementite between the ferrite crystal grain in the original mother metal, in process air cooler subsequently, makes to correct in district's mother metal and separates out granular tertiary cementite once more between the ferrite crystal grain.And then obtain more tough microstructure (Fig. 4).
Adopt the present invention that weathering steel is carried out flame shrinking; Hardness and the intensity that can make weathering steel flame shrinking district mother metal are near mother metal; Have apparent dispersoid particle to be distributed on the crystal boundary between the ferrite crystal grain in the microstructure of flame shrinking district metal, thereby the low-temperature impact work of flame shrinking district metal all can be higher than mother metal; When-40 ℃ of test temperatures, ballistic work A
KVReach 200J, be controlled at 600～650 ℃ same material test specimen ballistic work A for the highest heating in flame shrinking district
KV2.5 times (Fig. 5).
Description of drawings
Fig. 1 is the flame shrinking district mother metal hardness curve of different heating normality condition
Fig. 2 is the infrared thermometer emittance of actual demarcation and the relation curve of workpiece surface temperature
Fig. 3 is the thermal cycling curve in the flame shrinking district of HT-856D high temperature modification infrared thermometer monitoring
Fig. 4 is the tertiary cementite stereoscan photograph that disperse distributes on the F crystal boundary
Fig. 5 is flame shrinking district mother metal ballistic work--the transition temperature curve of different heating normality condition
Among Fig. 1 and Fig. 3: S355J2 is non-structural alloy steel, and S355J2W is a weathering steel.
Among Fig. 5: W1 is 800 ℃ of maximum heating temperatures; W2 is 750 ℃ of maximum heating temperatures; W3 is 700 ℃ of maximum heating temperatures; W4 is 650 ℃ of maximum heating temperatures.
Embodiment
Be example with the S355J2W weathering steel below, and combine accompanying drawing to set forth this process implementing step and technical essential:
(1) select to measure TR-32 ℃～1350 ℃, the measuring distance infrared thermometer more adjustable than 30: 1, measuring accuracy ± 1.5%, 0.1 ℃ of resolving power, time of response＜1 second, spectral response 8～14um, emittance 0.10～1.00; Specification sheets be to read over before using, principle and method of use grasped;
(2) according to the Flame Heating Temperature parameter of S355J2W weathering steel the emittance of infrared thermometer is carried out actual demarcation; So that accurately control heating schedule, (Fig. 2 is the infrared thermometer emittance of actual demarcation and the relation curve of S355J2W weathering steel workpiece surface temperature);
(3) confirm measuring distance than satisfying 30: 1, the area of measured workpiece is greater than 2 times of area of detection of infrared thermometer;
(4) be ready to S355J2W weathering steel heated parts, and heating location and the shape definite according to the flame shrinking technology of routine, the profile in the flame heating of on workpiece, drawing district, clear and definite heated perimeter;
(5) with neutral oxy-acetylene flame to workpiece heating zone even heating, and with infrared thermometer (Fig. 3 is the thermal cycling curve in the flame shrinking district of HT-856D high temperature modification infrared thermometer monitoring) monitored in the centre of heating zone in real time simultaneously; When no follow-up stress-removal thermal treatment, the workpiece heating zone must not be selected in the bigger tensile stress district of load;
(6) the flame shrinking district maximum heating temperature on the S355J2W weathering steel workpiece will be controlled at 730--750 ℃ (being near the AC1 temperature); After the maximum heating temperature of workpiece heating zone reaches this temperature; Kept again 2--3 minute, and guaranteed that there was the process of an equalizing temperature heating zone;
(7) let the heating zone get into as air-cooled condition, make workpiece naturally cool to room temperature.
It must be emphasized that: must not be on the workpiece same position repeating step (5)--the heating and cooling process of (7) repeatedly.
Technical essential of the present invention is:
1. guarantee that the flame shrinking district maximum heating temperature on the workpiece is controlled at 730～750 ℃;
2. the shape in flame heating district can adopt band shape, trilateral or point-like flexibly according to the situation of correcting welding residual deformation;
3. must not on the same heating location of workpiece, repeatedly repeat flame shrinking;
4. adopt the air cooling mode, without water-cooling pattern;
5. flame properties will be selected neutral flame, does not adopt carbonizing flame;
6. when no follow-up stress-removal thermal treatment, the heating zone is not selected in the bigger tensile stress district of load;
7. the steel with strong tendency of hardenability are not adopted flame shrinking technology.
Test-results of the present invention proves: when adopting above-mentioned technology to carry out flame shrinking; The hardness of flame shrinking district mother metal and intensity are near mother metal; There is apparent dispersoid particle to be distributed in (see figure 4) on the crystal boundary between the ferrite crystal grain in the microstructure of flame shrinking district metal; Thereby the low-temperature impact work of flame shrinking district metal all is higher than mother metal, when-40 ℃ of test temperatures, and ballistic work A
KVReach 200J, for flame shrinking district maximum heating temperature is controlled at the same material test specimen ballistic work A under 600～650 ℃ of conditions
KV2.5 times of (see figure 5)s.
Claims (1)
1. a weathering steel flame shrinking technology is characterized in that comprising the following steps:
(1) select to measure TR-32 ℃～1350 ℃, the measuring distance infrared thermometer more adjustable than 30: 1, measuring accuracy ± 1.5%, 0.1 ℃ of resolving power, time of response＜1 second, spectral response 8～14um, emittance 0.10～1.00; To read over specification sheets before using; Grasp principle and method of use, and the emittance of infrared thermometer is carried out actual demarcation according to workpiece flame shrinking district maximum heating temperature difference;
(2) confirm measuring distance than satisfying 30: 1, the area of object being measured is greater than 2 times of area of detection of infrared thermometer;
(3) be ready to the weathering steel heated parts, and heating location and the shape definite according to the flame shrinking technology of routine, the profile in the flame heating of on workpiece, drawing district, clear and definite heated perimeter;
(4) with neutral oxy-acetylene flame to workpiece heating zone even heating, with infrared thermometer the centre of heating zone is monitored in real time simultaneously; When no follow-up stress-removal thermal treatment, the workpiece heating zone must not be selected in the bigger tensile stress district of load;
(5) the flame shrinking district maximum heating temperature on the workpiece will be controlled at 730～750 ℃, and the emittance of infrared thermometer is 0.85; After the flame shrinking district maximum heating temperature on the workpiece reaches 730～750 ℃, kept again 2～3 minutes, guarantee that there is the process of an equalizing temperature heating zone;
(6) let the heating zone get into as air-cooled condition, make workpiece naturally cool to room temperature;
(7) must not be on the workpiece same position repeating step (4)--the heating and cooling process of (6) repeatedly.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012100967468A CN102605148A (en) | 2012-04-05 | 2012-04-05 | Weathering steel flame straightening process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012100967468A CN102605148A (en) | 2012-04-05 | 2012-04-05 | Weathering steel flame straightening process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102605148A true CN102605148A (en) | 2012-07-25 |
Family
ID=46522909
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012100967468A Pending CN102605148A (en) | 2012-04-05 | 2012-04-05 | Weathering steel flame straightening process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102605148A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104498688A (en) * | 2014-12-07 | 2015-04-08 | 吉林大学 | Flame straightening method of bogie frame of high speed train |
| CN107377682A (en) * | 2017-07-03 | 2017-11-24 | 南京中车浦镇城轨车辆有限责任公司 | Vehicle body of railway vehicle stainless sheet steel flame repairing technique |
-
2012
- 2012-04-05 CN CN2012100967468A patent/CN102605148A/en active Pending
Non-Patent Citations (2)
| Title |
|---|
| 罗辉等: "T 形结构焊接弯曲变形火焰矫正工艺分析", 《焊接技术》 * |
| 邵永帅等: "钢构件变形的火焰矫正方法", 《石油化工设备》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104498688A (en) * | 2014-12-07 | 2015-04-08 | 吉林大学 | Flame straightening method of bogie frame of high speed train |
| CN107377682A (en) * | 2017-07-03 | 2017-11-24 | 南京中车浦镇城轨车辆有限责任公司 | Vehicle body of railway vehicle stainless sheet steel flame repairing technique |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10308992B2 (en) | Method and system for selectively softening hot stamped parts by induction heating | |
| CN105200224B (en) | A kind of local post weld heat treatment method of quenched material very large vessels | |
| CN106191676B (en) | A kind of Varying-thickness method for customizing warm forming medium managese steel part | |
| CN104451082B (en) | A kind of preparation method of the average grain size 304 austenitic stainless steels less than 100nm | |
| CN1330930C (en) | Flexible measurement method for grain sizes of steel plate internal structure during rolling process | |
| CN106525563A (en) | Thermal simulation method of thermal-mechanical treatment of high strength automobile steel impact specimen | |
| CN106086653A (en) | A kind of warm forming medium managese steel part preparation method realizing capability gradient, equal thickness | |
| CN105548235A (en) | Test method for accurate determination of optimal heat treatment process for pearlitic steel rail | |
| Qian et al. | Correction of flow stress and determination of constitutive constants for hot working of API X100 pipeline steel | |
| CN103042070A (en) | Method for controlling strength distribution during high-strength steel pipe hot forming | |
| Huang et al. | Measurement and analysis of SHCCT diagram for CLAM steel | |
| CN102605148A (en) | Weathering steel flame straightening process | |
| CN102286655B (en) | Device and method for isothermal normalizing utilizing forging waste heat | |
| CN105598217B (en) | The constant temperature and pressure aligning method of titanium alloy die forging part warpage | |
| CN109916735A (en) | A kind of test device and test method of sheet metal thermal transient forming limit | |
| CN106248715A (en) | Thermal modeling test determines the test method of quenching rate of cooling | |
| CN103611735A (en) | Laminar cooling temperature monitoring method and device | |
| CN102162026B (en) | Method for annealing weld joint of 45 steel on narrow lap welding machine | |
| CN106282878A (en) | A kind of preparation method of galvanizing warm working high intensity medium managese steel part | |
| CN101736139B (en) | Organization control method of large-size pre-hardening type plastic die steel module | |
| CN103014263A (en) | Temperature control system of spheroidizing annealing furnace | |
| CN105256242B (en) | A kind of manufacture method of marine petroleum exploitation equipment forging blank | |
| CN110412067A (en) | A kind of thermal modeling test determines the test method of austempering temperature | |
| Skubisz et al. | Automated determination and on-line correction of emissivity coefficient in controlled cooling of drop forgings | |
| CN106248721A (en) | A kind of structural steel bar banded structure rank Fast Prediction method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20120725 |