CN107619921A - A kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond - Google Patents
A kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond Download PDFInfo
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Abstract
A kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond, step are：1）Get the martensite heat-resistant steel weld bond through low-temperature transformation ready, the heating coefficient needed for heat treatment is set；2）The fixation of thermocouple, fixed thermocouple is wrapped up with iron wire in the thermocouple far-end being incubated beyond width, with bandage by thermocouple and weld bond together banding fixed；3）Heat-preservation cotton is wrapped up, and heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；4）Induction coil is wound, and Medium frequency induction coil is wrapped in outside heat-preservation cotton, it is ensured that number of coils and coil-span meet to require；5）Heat treatment parameter is set；6）Frequency heating device startup/stopping, determining wiring and the errorless rear starter of heat treatment parameter；7）By martensite heat-resistant steel weld bond slow cooling to room temperature, outer coil and heat-preservation cotton are removed when being reduced to room temperature；The characteristics of simple with technological operation, cost is low, and production efficiency is high and environmentally friendly.
Description
Technical field
The invention belongs to weld bond processing technology field, and in particular at a kind of Medium frequency induction heat of martensite heat-resistant steel weld bond
Science and engineering skill.
Background technology
P91 belongs to ferrite type high-temperature refractory steel, is characterized in that weldability is poor, and heat treatment difficulty is big, weld bond easily occurs
The higher situation of hardness, has a strong impact on P91 weld bond quality, and P91 weld bonds are also known as martensite heat-resistant steel weld bond.At present, welded for P91
Mouth Technology for Heating Processing is still based on resistance heating technique.In terms of thermal treatment quality：The qualification rate of resistance heating Technology for Heating Processing is only
For 85%, wherein first-time qualification rate is no more than 60%.Because Frequency Induction Heating speed is fast, if Technology for Heating Processing is improper, it will tight
Ghost image rings P91 weld bond thermal treatment qualities, so as to influence weld bond properties, increases potential safety hazard.
The content of the invention
To overcome above-mentioned the deficiencies in the prior art, it is an object of the invention to provide a kind of intermediate frequency of martensite heat-resistant steel weld bond
Induction heat treatment process, there is the characteristics of technological operation is simple, and cost is low, and production efficiency is high and environmentally friendly.
To achieve the above object, the technical solution adopted by the present invention is：A kind of Medium frequency induction of martensite heat-resistant steel weld bond
Technology for Heating Processing, comprise the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that martensite is resistance to
Hot steel weld bond local environment, the heating coefficient of heat treatment is set；
Step 2, the fixation of thermocouple, specific practice are：Being incubated thermocouple far-end beyond width fixed heat is wrapped up with iron wire
Galvanic couple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, induction coil is set
Quantity and spread ratio；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond exists
When between 25-85mm, saturating magnetic infiltration coefficient is between 0.60 ~ 0.88；Maximum programming rate take 6250/ effective thickness DEG C/h with
Smaller value in 150 DEG C/h；Maximum cooling rate takes the smaller value in 6250/ weldment wall thickness DEG C/h and 150 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：Determine to start after wiring and heat treatment parameter are accurate
Device；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature.
The heating coefficient of heat treatment described in step 1 is 0.75 ~ 3.50.
The spread ratio of Medium frequency induction coil described in step 4 is 1.25 ~ 1.75；The number of turns of Medium frequency induction coil be 14 ~
19 circles.
The frequency of alternating current described in step 5 is 1600 ~ 2000Hz, and DC current values are 100 ~ 180A；Thermostat temperature is
700-750℃；Constant temperature time is relevant with pipeline wall thickness, and heat treatment temperature is heat-treated constant temperature in above-mentioned heat treatment constant temperature warm area
Time is 3-6min/mm；Maximum programming rate takes the smaller value in 6250/ effective thickness DEG C/h and 150 DEG C/h；Cooling rate is
6250 with the ratio of wall thickness, but maximum is no more than 150 DEG C/h.
Described thermostat temperature is 720-740 DEG C, constant temperature time 4min/mm.
The beneficial effects of the invention are as follows：
Compared with prior art, the present invention can control P91 weld bonds superficial hardness number between 200-240HB, once at heat
Qualification rate is managed more than 95%, and prior heat treatment process is difficult that P91 weld bond hardness numbers are reduced into below 240HB, first-time qualification rate
Only 60%；The present invention can substantially reduce the input of cost of labor, such as：Technological operation is simple, reduces the input of manpower, reduces
Personnel cost, production efficiency are notable；Cost input is cheap, particularly in terms of the input of auxiliary material, greatly reduces insulation
Cotton and the use cost of resistance heater；Energy-conserving and environment-protective, reduce the wasting of resources.
Embodiment
The present invention is described in further detail with reference to specific embodiment.
Embodiment 1
A kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond, comprises the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation（Material specification：P91, Ф 273 × 50）, carry out standard before heat treatment
It is standby, specific practice：Martensite heat-resistant steel weld bond local environment is checked, it is 0.75 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction coil
The number of turns is 14 circles, and the spread ratio of Medium frequency induction coil is 1.25, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond exists
During 50mm, saturating magnetic infiltration coefficient is 0.80；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 1600Hz, DC current
For 100A；Thermostat temperature is 700 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 6min/mm；Cooling speed
Degree maximum is no more than 125 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature.
Step 8, hardness number detects, and specific practice is：Hardness determination is carried out using portable hardometer, it is heat-resisting in martensite
Each detection faces of steel weld bond take 5 points, average, and detection position should be polished before detection, ensure that detection faces are bright and clean, neat
It is flat；
Step 9, heat treatment hardness value result of determination, specific practice are：The hardness number minimum value of detection position is 255HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 268HB, average hardness value 261HB, above-mentioned hardness number
Hardness number is qualified.
Step 10, metallographic structure result of determination, specific practice are：Weld seam metallographic structure is tempered martensite/tempering Soxhlet
Body tissue, δ-ferrite is not found in metallographic structure, judge that metallographic structure is qualified.
Embodiment 2
A kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond, comprises the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation（Material specification：P91, Ф 485 × 85）, carry out standard before heat treatment
It is standby, specific practice：Martensite heat-resistant steel weld bond local environment is checked, it is 0.75 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction coil
The number of turns is 19 circles, and the spread ratio of Medium frequency induction coil is 1.50, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, frequency and DC current values, when the wall thickness of martensite heat-resistant steel weld bond is in 50mm, thoroughly
Magnetic infiltration coefficient is 0.88；Maximum programming rate takes 83 DEG C/h；The frequency of alternating current is 2000Hz, DC current values 150A；
Thermostat temperature is 750 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 3min/mm；Cooling rate maximum
No more than 73 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature.
Step 8, hardness number detects, and specific practice is：Hardness determination is carried out using portable hardometer, it is heat-resisting in martensite
Each detection faces of steel weld bond take 5 points, average, and detection position should be polished before detection, ensure that detection faces are bright and clean, neat
It is flat；
Step 9, heat treatment hardness value result of determination, specific practice are：The hardness number minimum value of detection position is 208HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 218HB, average hardness value 211HB, above-mentioned hardness number
Hardness number is qualified.
Step 10, metallographic structure result of determination, specific practice are：Weld seam metallographic structure is tempered martensite/tempering Soxhlet
Body tissue, δ-ferrite is not found in metallographic structure, judge that metallographic structure is qualified.
Embodiment 3
A kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond, comprises the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation（Material specification：P91, Ф 273 × 50）, carry out standard before heat treatment
It is standby, specific practice：Martensite heat-resistant steel weld bond local environment is checked, it is 0.75 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction coil
The number of turns is 14 circles, and the spread ratio of Medium frequency induction coil is 1.75, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond exists
During 50mm, saturating magnetic infiltration coefficient is 0.80；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 1800Hz, DC current
For 100A；Thermostat temperature is 720 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4min/mm；Cooling speed
Degree maximum is no more than 125 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature.
Step 8, hardness number detects, and specific practice is：Hardness determination is carried out using portable hardometer, it is heat-resisting in martensite
Each detection faces of steel weld bond take 5 points, average, and detection position should be polished before detection, ensure that detection faces are bright and clean, neat
It is flat；
Step 9, heat treatment hardness value result of determination, specific practice are：The hardness number minimum value of detection position is 228HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 244HB, average hardness value 235HB, above-mentioned hardness number
Hardness number is qualified.
Step 10, metallographic structure result of determination, specific practice are：Weld seam metallographic structure is tempered martensite/tempering Soxhlet
Body tissue, δ-ferrite is not found in metallographic structure, judge that metallographic structure is qualified.
Embodiment 4
A kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond, comprises the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation（Material specification：P91, Ф 324 × 45）, carry out standard before heat treatment
It is standby, specific practice：Martensite heat-resistant steel weld bond local environment is checked, it is 0.75 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction coil number
It is 1.33 to measure as 14 circles, Medium frequency induction coil-span coefficient, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond exists
During 45mm, saturating magnetic infiltration coefficient is 0.78；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current
For 100A；Thermostat temperature is 727 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4min/mm；Cooling speed
The ratio for 6250 and wall thickness is spent, but maximum is no more than 138 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature；
Step 8, hardness number detects, and specific practice is：Hardness determination is carried out using portable hardometer, welded in martensite heat-resistant steel
Each detection faces of mouth take 5 points, average, detection position should be polished before detection, ensure that detection faces are bright and clean, flush；
Step 9, heat treatment hardness value result of determination, specific practice are：The hardness number minimum value of detection position is 220HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 234HB, average hardness value 228HB, above-mentioned hardness number
Hardness number is qualified；
Step 10, metallographic structure result of determination, specific practice are：Weld seam metallographic structure is tempered martensite/tempered sorbite group
Knit, do not find δ-ferrite in metallographic structure, judge that metallographic structure is qualified.
Embodiment 5
A kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond, comprises the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation（Material specification：P91, Ф 735 × 28）, carry out standard before heat treatment
It is standby, specific practice：Martensite heat-resistant steel weld bond local environment is checked, it is 3.50 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction coil number
It is 1.33 to measure as 17 circles, Medium frequency induction coil-span coefficient, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond exists
During 28mm, saturating magnetic infiltration coefficient is 0.64；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current
For 180A；Thermostat temperature is 735 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4min/mm；Cooling speed
The ratio for 6250 and wall thickness is spent, but maximum is no more than 150 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature；
Step 8, hardness number detects, and specific practice is：Hardness determination is carried out using portable hardometer, welded in martensite heat-resistant steel
Each detection faces of mouth take 5 points, average, detection position should be polished before detection, ensure that detection faces are bright and clean, flush；
Step 9, heat treatment hardness value result of determination, specific practice are：The hardness number minimum value of detection position is 232HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 243HB, average hardness value 237HB, above-mentioned hardness number
Hardness number is qualified.
Step 10, metallographic structure result of determination, specific practice are：Weld seam metallographic structure is tempered martensite/tempering Soxhlet
Body tissue, δ-ferrite is not found in metallographic structure, judge that metallographic structure is qualified.
Embodiment 6
A kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond, comprises the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation（Material specification：P91, Ф 324 × 42）, carry out standard before heat treatment
It is standby, specific practice：Martensite heat-resistant steel weld bond local environment is checked, it is 1.30 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction coil number
It is 1.33 to measure as 14 circles, Medium frequency induction coil-span coefficient, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond exists
During 42mm, saturating magnetic infiltration coefficient is 0.76；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current
For 120A；Thermostat temperature is 730 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4min/mm；Cooling speed
The ratio for 6250 and wall thickness is spent, but maximum is no more than 148 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature；
Step 8, hardness number detects, and specific practice is：Hardness determination is carried out using portable hardometer, welded in martensite heat-resistant steel
Each detection faces of mouth take 5 points, average, detection position should be polished before detection, ensure that detection faces are bright and clean, flush；
Step 9, heat treatment hardness value result of determination, specific practice are：The hardness number minimum value of detection position is 212HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 226HB, average hardness value 216HB, above-mentioned hardness number
Hardness number is qualified.
Step 10, metallographic structure result of determination, specific practice are：Weld seam metallographic structure is tempered martensite/tempering Soxhlet
Body tissue, δ-ferrite is not found in metallographic structure, judge that metallographic structure is qualified.
Embodiment 7
A kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond, comprises the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation（Material specification：P91, Ф 559 × 25）, carry out standard before heat treatment
It is standby, specific practice：Martensite heat-resistant steel weld bond local environment is checked, it is 2.50 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, induction coil quantity is
14, induction coil spread ratio is 1.33, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond exists
During 25mm, saturating magnetic infiltration coefficient is 0.60；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current
For 150A；Thermostat temperature is 730 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4min/mm；Cooling speed
The ratio for 6250 and wall thickness is spent, but maximum is no more than 150 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature；
Step 8, hardness number detects, and specific practice is：Hardness determination is carried out using portable hardometer, welded in martensite heat-resistant steel
Each detection faces of mouth take 5 points, average, detection position should be polished before detection, ensure that detection faces are bright and clean, flush；
Step 9, heat treatment hardness value result of determination, specific practice are：The hardness number minimum value of detection position is 235HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 244HB, average hardness value 238HB, above-mentioned hardness number
Hardness number is qualified.
Step 10, metallographic structure result of determination, specific practice are：Weld seam metallographic structure is tempered martensite/tempering Soxhlet
Body tissue, δ-ferrite is not found in metallographic structure, judge that metallographic structure is qualified.
Width of heating：Width of heating crosses conference and causes the wasting of resources, and width of heating deficiency can influence thermal treatment quality, therefore
Width of heating should《Weld heat treatment technics code in DL/T 819-2010 thermal power plants》It is required that it is defined.
Wire circle：Martensite heat-resistant steel weld bond heating power and width of heating have an impact to wire circle jointly, its
Middle heating power is relevant with heat treatment heating coefficient and pipeline specifications.Be heat-treated heating coefficient is with input current, frequency, radiating
Number, material density, thermal conductivity, the Effects of Heat Treatment factor, net sectional area, magnetic conductivity, pipeline wall thickness, coil outer diameter and heating are wide
The factors such as degree are relevant, and heating coefficient is between 0.75-3.50.
Medium frequency induction coil-span：Medium frequency induction coil coil-span can be by between spread ratio and coil diameter
Relation is calculated, and Medium frequency induction coil coil-span=spread ratio × coil diameter, spread ratio scope is 1.25 ~ 1.75
Between.
Firing rate：According to P91 material features, heat treatment firing rate is unsuitable too fast, and firing rate has with effective thickness
Close, effective thickness is relevant with pipeline wall thickness and saturating magnetic permeance coefficient, and saturating magnetic permeance coefficient scope is between 0.60 ~ 0.88.
Constant temperature time：Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is calculated by 3-6min/mm.
It is as follows to relevant data that intermediate-frequency induction heating experiment is carried out with martensite heat-resistant steel weld bond：
1）Thermally treated experiment, comprehensive each technological parameter, draws following applicable heat treatment process parameter：
Be heat-treated thermostat temperature be 700-750 DEG C, constant temperature time 3-6min/mm is calculated, specific constant temperature time optionally and
It is fixed；1600 ~ 2000Hz of frequency, 100 ~ 180A of DC current, maximum programming rate take 6250/ effective thickness DEG C/h and 150 DEG C/h
In smaller value；Maximum cooling rate takes the smaller value in 6250/ weldment wall thickness DEG C/h and 150 DEG C/h；The number of turns regards pipeline specifications
Depending on situation, but wire circle meets no less than 10 circles, winding space《The welding heat treatment of DL/T 819-2010 thermal power plants
Technical regulation》Requirement.
2）Medium-frequency heat processing equipment：Peak power 100KW, DC current maximum are 200A, and frequency maximum range is
3000Hz, coil diameter 15mm.
3）Medium frequency induction tests material specification：Ф273×50mm；Ф324×45mm；Ф324×42；Ф559×25mm；
Ф735×28mm；Ф585×85.
4）According to《DL/T868-2014 qualification of welding procedure codes》Content, deploy every mechanical property test.Mechanical property
In energy index, traditional resistor heating technique is difficult that P91 weld bond case hardnesses are reduced into below 240HB, impact flexibility desired value
Relatively low, specific targets are as shown in table 1.And Frequency Induction Heating technique, P91 weld bonds case hardness and impact flexibility index are superior to
Traditional resistance heating technique.Frequency Induction Heating technique, from the point of view of indices, plasticity index and tensile property are good, punching
Hit toughness to meet the requirements, superficial hardness number is controlled between 200-240HB.Above-mentioned all properties meet《DL/T868-2014
Qualification of welding procedure code》With《DL/T869-2012 thermal power plants welding technique code》Related request.Specific detection knot
Fruit is as shown in table 1.
。
Claims (10)
1. a kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond, it is characterised in that comprise the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that martensite is resistance to
Hot steel weld bond local environment, the heating coefficient needed for heat treatment is set；
Step 2, the fixation of thermocouple, specific practice are：Being incubated thermocouple far-end beyond width fixed heat is wrapped up with iron wire
Galvanic couple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, finally using bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction line is set
Number of turns amount and coil-span coefficient；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond is 25
When between ~ 85mm, saturating magnetic infiltration coefficient is between 0.60 ~ 0.88；Maximum programming rate takes 6250/ effective thickness DEG C/h and 150
DEG C/h in smaller value；Maximum cooling rate takes the smaller value in 6250/ weldment wall thickness DEG C/h and 150 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：Determine to start after wiring and heat treatment parameter are accurate
Device；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature.
A kind of 2. intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond according to claim 1, it is characterised in that
The heating coefficient of heat treatment described in step 1 is 0.75 ~ 3.50.
A kind of 3. intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond according to claim 1, it is characterised in that
The spread ratio of Medium frequency induction coil described in step 4 is 1.25 ~ 1.75；The number of turns of Medium frequency induction coil is 14 ~ 19 circles.
A kind of 4. intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond according to claim 1, it is characterised in that
The frequency of alternating current described in step 5 is 1600 ~ 2000Hz, and DC current values are 100 ~ 180A；Thermostat temperature is 700-750
℃；Constant temperature time is relevant with pipeline wall thickness, and for heat treatment temperature in above-mentioned heat treatment constant temperature warm area, heat treatment constant temperature time is 3-
6min/mm；Maximum programming rate takes the smaller value in 6250/ effective thickness DEG C/h and 150 DEG C/h；Cooling rate is 6250 and wall
Thick ratio, but maximum is no more than 150 DEG C/h.
A kind of 5. intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond according to claim 4, it is characterised in that
Described thermostat temperature is 720-740 DEG C, and constant temperature time is 4 ~ 4.5min/mm.
A kind of 6. intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond according to claim 5, it is characterised in that
Described constant temperature time is 4min/mm.
A kind of 7. intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond according to claim 1, it is characterised in that
Comprise the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that martensite is resistance to
Hot steel weld bond local environment, it is 0.75 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction coil number
Measure as 14, Medium frequency induction coil-span coefficient is 1.33, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, frequency and DC current values, when the wall thickness of martensite heat-resistant steel weld bond is in 45mm, thoroughly
Magnetic infiltration coefficient is 0.78；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current values 100A；It is permanent
Temperature is 727 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4min/mm；Cooling rate be 6250 with
The ratio of wall thickness, but maximum is no more than 138 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature.
A kind of 8. intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond according to claim 1, it is characterised in that
Comprise the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that martensite is resistance to
Hot steel weld bond local environment, it is 3.50 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction coil number
Measure as 17, Medium frequency induction coil-span coefficient is 1.33, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond exists
During 28mm, saturating magnetic infiltration coefficient is 0.64；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current
Value 180A；Thermostat temperature is 735 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4min/mm；Cooling speed
The ratio for 6250 and wall thickness is spent, but maximum is no more than 150 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature.
A kind of 9. intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond according to claim 1, it is characterised in that
Comprise the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that martensite is resistance to
Hot steel weld bond local environment, it is 1.30 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction coil number
Measure as 14, Medium frequency induction coil-span coefficient is 1.33, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond exists
During 42mm, saturating magnetic infiltration coefficient is 0.76；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current
It is worth for 120A；Thermostat temperature is 730 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4min/mm；Cooling
Speed is 6250 ratios with wall thickness, but maximum is no more than 148 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature.
10. a kind of intermediate-frequency induction heating technique of martensite heat-resistant steel weld bond according to claim 1, its feature exist
In comprising the following steps：
Step 1, the martensite heat-resistant steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that martensite is resistance to
Hot steel weld bond local environment, it is 2.50 to set the heating coefficient needed for heat treatment；
Step 2, the fixation of thermocouple, specific practice are：Wrapped up and fixed with iron wire in the thermocouple far-end being incubated beyond width
Thermocouple, then with bandage by thermocouple and weld bond together banding fixed；
Step 3, heat-preservation cotton is wrapped up, specific practice：Heat-preservation cotton is wrapped in the outside of weld bond, with bandage banding fixed；
Step 4, induction coil is wound, specific practice：Medium frequency induction coil is wrapped in outside heat-preservation cotton, Medium frequency induction coil number
Measure as 14, Medium frequency induction coil-span coefficient is 1.33, meets heating power and code requirement；
Step 5, heat treatment parameter is set, and specific practice is that the technological parameter set in frequency heating device includes：Constant temperature temperature
Degree, lifting/lowering temperature speed, constant temperature time, the frequency and DC current values of alternating current, when the wall thickness of martensite heat-resistant steel weld bond exists
During 25mm, saturating magnetic infiltration coefficient is 0.60；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current
For 150A；Thermostat temperature is 730 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4min/mm；Cooling speed
The ratio for 6250 and wall thickness is spent, but maximum is no more than 150 DEG C/h；
Step 6, frequency heating device startup/stopping, specific practice are：First ensure that all wiring have connected, determine wiring
With the accurate rear starter of heat treatment parameter；
Step 7, it is by martensite heat-resistant steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Martensite heat-resistant steel weld bond slow cooling state is kept, outer coil and heat-preservation cotton are removed when temperature is reduced to room temperature.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108330271A (en) * | 2018-03-21 | 2018-07-27 | 彭娟 | A kind of intermediate-frequency induction heating technique of pipe welding port |
| CN109321742A (en) * | 2018-12-13 | 2019-02-12 | 王立翀 | A kind of Medium frequency induction secondary heat treatment technique of pipe welding port |
| CN109825680A (en) * | 2019-03-12 | 2019-05-31 | 中核工程咨询有限公司 | One kind being used for big wall thickness bimetal compound pipeline heat treatment method |
| CN112029983A (en) * | 2020-09-02 | 2020-12-04 | 中国电建集团山东电力建设第一工程有限公司 | Postweld heat treatment process for martensite heat-resistant steel G115 large-diameter thick-wall pipeline |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5544513A (en) * | 1978-09-22 | 1980-03-28 | High Frequency Heattreat Co Ltd | Method and apparatus for heat treatment of heat resistant super alloy by high frequency induction heating |
| JP2009173985A (en) * | 2008-01-23 | 2009-08-06 | Jfe Steel Corp | Heat-treatment method of electric resistance welded steel pipe |
| CN102230066A (en) * | 2011-06-22 | 2011-11-02 | 中国石化集团第十建设公司 | Local heat treatment process for welding seam of 12CrlMoV pipe |
| CN102618713A (en) * | 2012-03-10 | 2012-08-01 | 广东省韶关粤江发电有限责任公司 | Heat treatment method for welding SA335-P91/P92 steel by ultra-supercritical coal-fired power plant |
| CN102796863A (en) * | 2012-07-23 | 2012-11-28 | 宁夏共享集团有限责任公司 | Method used for local postweld heat treatment of large-size steel casting after rewelding |
| CN104561509A (en) * | 2014-12-26 | 2015-04-29 | 中国核工业二三建设有限公司 | Method for assisting heat treatment of steel pipe welding seams |
| CN104694716A (en) * | 2015-03-10 | 2015-06-10 | 扬中市盛达电器制造有限责任公司 | Pipeline welding heat treatment intermediate frequency induction heating technology and device |
| CN105219944A (en) * | 2015-10-30 | 2016-01-06 | 中国石油化工股份有限公司 | The heat treating method of the shaping weld seam of a kind of drilling rod |
-
2017
- 2017-09-29 CN CN201710905537.6A patent/CN107619921B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5544513A (en) * | 1978-09-22 | 1980-03-28 | High Frequency Heattreat Co Ltd | Method and apparatus for heat treatment of heat resistant super alloy by high frequency induction heating |
| JP2009173985A (en) * | 2008-01-23 | 2009-08-06 | Jfe Steel Corp | Heat-treatment method of electric resistance welded steel pipe |
| CN102230066A (en) * | 2011-06-22 | 2011-11-02 | 中国石化集团第十建设公司 | Local heat treatment process for welding seam of 12CrlMoV pipe |
| CN102618713A (en) * | 2012-03-10 | 2012-08-01 | 广东省韶关粤江发电有限责任公司 | Heat treatment method for welding SA335-P91/P92 steel by ultra-supercritical coal-fired power plant |
| CN102796863A (en) * | 2012-07-23 | 2012-11-28 | 宁夏共享集团有限责任公司 | Method used for local postweld heat treatment of large-size steel casting after rewelding |
| CN104561509A (en) * | 2014-12-26 | 2015-04-29 | 中国核工业二三建设有限公司 | Method for assisting heat treatment of steel pipe welding seams |
| CN104694716A (en) * | 2015-03-10 | 2015-06-10 | 扬中市盛达电器制造有限责任公司 | Pipeline welding heat treatment intermediate frequency induction heating technology and device |
| CN105219944A (en) * | 2015-10-30 | 2016-01-06 | 中国石油化工股份有限公司 | The heat treating method of the shaping weld seam of a kind of drilling rod |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108330271A (en) * | 2018-03-21 | 2018-07-27 | 彭娟 | A kind of intermediate-frequency induction heating technique of pipe welding port |
| CN109321742A (en) * | 2018-12-13 | 2019-02-12 | 王立翀 | A kind of Medium frequency induction secondary heat treatment technique of pipe welding port |
| CN109825680A (en) * | 2019-03-12 | 2019-05-31 | 中核工程咨询有限公司 | One kind being used for big wall thickness bimetal compound pipeline heat treatment method |
| CN109825680B (en) * | 2019-03-12 | 2020-12-08 | 中核工程咨询有限公司 | Heat treatment method for large-wall-thickness bimetal composite pipeline |
| CN112029983A (en) * | 2020-09-02 | 2020-12-04 | 中国电建集团山东电力建设第一工程有限公司 | Postweld heat treatment process for martensite heat-resistant steel G115 large-diameter thick-wall pipeline |
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| CN107619921B (en) | 2019-01-25 |
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