CN107619922A - A kind of intermediate-frequency induction heating technique of heat-resistant high alloy steel weld bond - Google Patents
A kind of intermediate-frequency induction heating technique of heat-resistant high alloy steel weld bond Download PDFInfo
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Abstract
A kind of intermediate-frequency induction heating technique of heat-resistant high alloy steel weld bond, step are：1）Get the heat-resistant high alloy 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 heat-resistant high alloy 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 heat-resistant high alloy steel weld bond
Science and engineering skill.
Background technology
P92 belongs to heat-resistant high alloy steel, is characterized in that weldability is poor, and heat treatment difficulty is big, and it is inclined weld bond hardness easily occur
High situation, has a strong impact on P92 weld bond quality, and P92 weld bonds are also known as heat-resistant high alloy steel weld bond.At present, at for P92 weld bonds heat
Science and engineering skill 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 80%,
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 have a strong impact on
P92 weld bond thermal treatment qualities, so as to influence weld bond properties, increase 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 heat-resistant high alloy 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 heat-resistant high alloy steel weld bond
Technology for Heating Processing, comprise the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that high alloy 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, 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 line is set
The quantity and spread ratio of circle；
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 heat-resistant high alloy steel weld bond wall thickness 32-84mm it
Between when, saturating magnetic infiltration coefficient is between 0.69 ~ 0.88；Maximum programming rate is taken in 6250/ effective thickness DEG C/h and 150 DEG C/h
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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 induction coil described in step 4 is 1.25 ~ 1.75.
The frequency of alternating current described in step 5 is 1600 ~ 2000Hz, 100 ~ 180A of DC current；Thermostat temperature is 700-
750℃；Constant temperature time is relevant with pipeline wall thickness, and heat treatment temperature is heat-treated constant temperature time in above-mentioned heat treatment constant temperature warm area
For 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 730-750 DEG C, and constant temperature time is 4 ~ 5min/mm.
Described constant temperature time is 4.5min/mm.
The beneficial effects of the invention are as follows：
Compared with prior art, the present invention can control P92 weld bonds superficial hardness number between 210-250HB, once at heat
Qualification rate is managed more than 95%, and prior heat treatment process is difficult that P92 weld bond hardness numbers are reduced into below 250HB, 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 heat-resistant high alloy steel weld bond, comprises the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation（Material specification：P92, Ф 273 × 58）, carry out standard before heat treatment
It is standby, specific practice：Heat-resistant high alloy 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, 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, frequency and DC current values, when the wall thickness of heat-resistant high alloy steel weld bond is in 58mm, thoroughly
Magnetic infiltration coefficient is 0.83；Maximum programming rate takes 130 DEG C/h；The frequency of alternating current is 1600Hz, DC current 100A；Constant temperature
Temperature is 700 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 6min/mm；Cooling rate maximum does not surpass
Cross 107 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 high alloy
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 256HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 267HB, average hardness value 262HB, 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 heat-resistant high alloy steel weld bond, comprises the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation（Material specification：P92, Ф 460 × 84）, carry out standard before heat treatment
It is standby, specific practice：Heat-resistant high alloy 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, 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 heat-resistant high alloy steel weld bond is in 84mm, thoroughly
Magnetic infiltration coefficient is 0.88；Maximum programming rate takes 84 DEG C/h；The frequency of alternating current is 2000Hz, DC current 150A；Constant temperature
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 does not surpass
Cross 74 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 high alloy
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 221HB, average hardness value 214HB, 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 heat-resistant high alloy steel weld bond, comprises the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation（Material specification：P92, Ф 273 × 58）, carry out standard before heat treatment
It is standby, specific practice：Heat-resistant high alloy 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, 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, frequency and DC current values, when the wall thickness of heat-resistant high alloy steel weld bond is in 58mm, thoroughly
Magnetic infiltration coefficient is 0.83；Maximum programming rate takes 130 DEG C/h；The frequency of alternating current is 1800Hz, DC current 100A；Constant temperature
Temperature is 730 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4.5min/mm；Cooling rate maximum is not
More than 107 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 high alloy
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 237HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 248HB, average hardness value 243HB, 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 heat-resistant high alloy steel weld bond, comprises the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation（Material specification：P92, Ф 694 × 39）, carry out standard before heat treatment
It is standby, specific practice：Heat-resistant high alloy steel weld bond local environment is checked, it is 2.00 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, 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 16 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, frequency and DC current values, when the wall thickness of heat-resistant high alloy steel weld bond is in 39mm, thoroughly
Magnetic infiltration coefficient is 0.74；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current 180A；Constant temperature
Temperature is 740 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4.5min/mm；Cooling rate be 6250 with
The ratio of wall thickness, 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 heat-resistant high alloy 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 226HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 238HB, average hardness value 232HB, 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 heat-resistant high alloy steel weld bond, comprises the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation（Material specification：P92, Ф 442 × 60）, carry out standard before heat treatment
It is standby, specific practice：Heat-resistant high alloy 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, 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 heat-resistant high alloy steel weld bond is in 60mm, thoroughly
Magnetic infiltration coefficient is 0.83；Maximum programming rate takes 125 DEG C/h；The frequency of alternating current is 2000Hz, DC current 130A；Constant temperature
Temperature is 735 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4.5min/mm；Cooling rate be 6250 with
The ratio of wall thickness, but maximum is no more than 104 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 heat-resistant high alloy 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 224HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 236HB, 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/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 heat-resistant high alloy steel weld bond, comprises the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation（Material specification：P92, Ф 540 × 32）, carry out standard before heat treatment
It is standby, specific practice：Heat-resistant high alloy 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, 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, frequency and DC current values, when the wall thickness of heat-resistant high alloy steel weld bond is in 32mm, thoroughly
Magnetic infiltration coefficient is 0.69；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current 150A；Constant temperature
Temperature is 735 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4.5min/mm；Cooling rate be 6250 with
The ratio of wall thickness, 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 heat-resistant high alloy 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 248HB, average hardness value 241HB, 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 heat-resistant high alloy steel weld bond, comprises the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation（Material specification：P92, Ф 694 × 40）, carry out standard before heat treatment
It is standby, specific practice：Heat-resistant high alloy steel weld bond local environment is checked, it is 2.00 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, 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
17, 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, frequency and DC current values, when the wall thickness of heat-resistant high alloy steel weld bond is in 40mm, thoroughly
Magnetic infiltration coefficient is 0.75；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current 180A；Constant temperature
Temperature is 745 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4.5min/mm；Cooling rate be 6250 with
The ratio of wall thickness, 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 heat-resistant high alloy 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 213HB, maximum
It is worth and judges heat treatment within 185-270HB code requirement for 228HB, average hardness value 220HB, 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.
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：Heat-resistant high alloy 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：Induction coil coil-span can pass through the relation between spread ratio and coil diameter
It is calculated, Medium frequency induction coil coil-span=spread ratio × coil diameter, Medium frequency induction coil coil-span coefficient range
Between 1.25 ~ 1.75.
Firing rate：According to P92 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 0.69 ~ 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 heat-resistant high alloy 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：Ф273×58mm；Ф694×40mm；Ф442×60；Ф540×32；Ф
460×84mm；Ф694×39mm.
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 P92 weld bond case hardnesses are reduced into below 250HB, impact flexibility desired value
Relatively low, specific targets are as shown in table 1.And Frequency Induction Heating technique, P92 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 210-250HB.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 heat-resistant high alloy steel weld bond, it is characterised in that comprise the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that high alloy 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, 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 line is set
Number of turns amount 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, frequency and DC current values, when heat-resistant high alloy steel weld bond wall thickness 32 ~ 84mm it
Between when, saturating magnetic infiltration coefficient is between 0.69 ~ 0.88；Maximum programming rate is taken in 6250/ effective thickness DEG C/h and 150 DEG C/h
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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 heat-resistant high alloy 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 heat-resistant high alloy 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 heat-resistant high alloy steel weld bond according to claim 1, it is characterised in that
The frequency of alternating current described in step 5 is 1600 ~ 2000Hz, 100 ~ 180A of DC current；Thermostat temperature is 700-750 DEG C；It is permanent
The warm 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 thickness
Ratio, but maximum is no more than 150 DEG C/h.
A kind of 5. intermediate-frequency induction heating technique of heat-resistant high alloy steel weld bond according to claim 4, it is characterised in that
Described thermostat temperature is 730-750 DEG C, and constant temperature time is 4 ~ 5min/mm.
A kind of 6. intermediate-frequency induction heating technique of heat-resistant high alloy steel weld bond according to claim 5, it is characterised in that
Described constant temperature time is 4.5min/mm.
A kind of 7. intermediate-frequency induction heating technique of heat-resistant high alloy steel weld bond according to claim 1, it is characterised in that
Comprise the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that high alloy is resistance to
Hot steel weld bond local environment, it is 2.00 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, 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 16 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, frequency and DC current values, when the wall thickness of heat-resistant high alloy steel weld bond is in 39mm, thoroughly
Magnetic infiltration coefficient is 0.74；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current 180A；Constant temperature
Temperature is 740 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4.5min/mm；Cooling rate be 6250 with
The ratio of wall thickness, 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 heat-resistant high alloy steel weld bond according to claim 1, it is characterised in that
Comprise the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that high alloy 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, 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, 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, frequency and DC current values, when the wall thickness of heat-resistant high alloy steel weld bond is in 60mm, thoroughly
Magnetic infiltration coefficient is 0.83；Maximum programming rate takes 125 DEG C/h；The frequency of alternating current is 2000Hz, DC current 130A；Constant temperature
Temperature is 735 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4.5min/mm；Cooling rate be 6250 with
The ratio of wall thickness, but maximum is no more than 104 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 heat-resistant high alloy steel weld bond according to claim 1, it is characterised in that
Comprise the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that high alloy 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, 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, intermediate frequency 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 heat-resistant high alloy steel weld bond is in 32mm, thoroughly
Magnetic infiltration coefficient is 0.69；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current 150A；Constant temperature
Temperature is 735 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4.5min/mm；Cooling rate be 6250 with
The ratio of wall thickness, 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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 heat-resistant high alloy steel weld bond according to claim 1, its feature exist
In comprising the following steps：
Step 1, the heat-resistant high alloy steel weld bond through low-temperature transformation, prepare before carrying out heat treatment, specific practice：Check that high alloy is resistance to
Hot steel weld bond local environment, it is 2.00 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, 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, frequency and DC current values, when the wall thickness of heat-resistant high alloy steel weld bond is in 40mm, thoroughly
Magnetic infiltration coefficient is 0.75；Maximum programming rate takes 150 DEG C/h；The frequency of alternating current is 2000Hz, DC current 180A；Constant temperature
Temperature is 745 DEG C；Constant temperature time is relevant with pipeline wall thickness, and heat treatment constant temperature time is 4.5min/mm；Cooling rate be 6250 with
The ratio of wall thickness, 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 heat-resistant high alloy steel weld bond slow cooling to room temperature, specific practice：, should when heat treatment temperature is reduced to 300 DEG C
Heat-resistant high alloy 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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| CN108330271A (en) * | 2018-03-21 | 2018-07-27 | 彭娟 | A kind of intermediate-frequency induction heating technique of pipe welding port |
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