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110 Questions About Metal Heat Treatment (Part 5)

81.What is the cause of outlet flap failure?

The outlet flap connecting shaft deforms and falls off, so the steel pipe on the diagonal arm cannot be sent to the front roller table of the furnace.

The operation panel exit flip plate lifting and lowering with light button lights are not on, indicating the proximity switch fault, to find a spot inspection and repair.

If the signals of two material level sensors on the front roller of the return furnace fail, the steel tube cannot be sent to the return furnace. In addition, the continuous turning of the exit flap will occur, resulting in the accumulation of more than two steel pipes on the hearth before the furnace.

82.What causes the failure of the hydraulic station?

High oil temperature and low oil temperature; Low oil level and lack of oil; Filter pollution and other phenomena, will cause hydraulic station failure.

83. What causes the failure of the oil pump?

Lack of oil, low-pressure phenomenon, will cause the fault of the dry pump, it is necessary to add dry oil in time.

84. What are the consequences of inverter failure?

Wheaton lever motor and quenching rotary bench which will cause no low and high-speed rotation switch of feeding device.

85. What causes water treatment failure?

The imbalance of internal and external injection water quantity and return water quantity will result in the failure of automatic quenching. The energy department should be informed to adjust the balance of inlet and return water quantity in time.

86. What is the fault of high-pressure water descaling?

The water spray ring is damaged and the circulation pipe is blocked with sundries.

If the above equipment fault is found, it should be reported to the site for inspection and maintenance in time.

What are the common faults of the heat treatment furnace?

The burner is mainly extinguished, the burner cannot be ignited, the current, gas, airflow is insufficient, the burner cannot be reset after extinguished, the hydraulic pump automatically shuts off, etc.

87. How to solve the burner extinguish?

Manually reset burner. Turn off the gas hand valve before the burner and open the air hand valve to blow and sweep for 15 minutes before ignition. If the burner cannot be lit at one time, close the gas hand valve immediately in front of the burner and clean the furnace with air for at least 15 minutes before lighting.

88. How to solve the problem that the burner cannot ignite?

1. Check whether the ignition device fails.

2. Check whether the pressure of fire, air, and natural gas is normal.

3. Find electrical and instrumentation workers.

89. How to deal with insufficient current, gas, and airflow?

1. When the current is interrupted, the gas pressure is insufficient, and the air pressure is insufficient, the safety rotating slide valve will automatically close, cut off the gas supply from the main valve, and prevent the gas from continuing to enter the furnace to avoid danger.

2. The fault signal lamp and alarm will start automatically, and the operator should deal with it as soon as possible.

3. If the current of the furnace is interrupted, the emergency power should be supplied immediately to keep the recirculation fan running.

4. Immediately close the gas hand valve in front of the burner.

5. Set the gas pressure controller, combustion air controller, temperature controller, and proportional controller to the “manual” position.

6. Manually controlled full open furnace pressure control valve.

7. After handling the fault, restart the operation according to the ignition procedure.

90. How to solve the problem of unable to reset the burner after it goes out?

When it is confirmed that the burner cannot ignite, the reason may be that there is too much dust in the flame observer to observe the flame. The solenoid valve will automatically cut off and the burner will go out. At this time, just wipe off the dust on the flame observer in front of the burner and start a fire once.

91. How to solve the problem after the hydraulic pump shuts off automatically?

When walking beam or water quenching device, the action is controlled by hydraulic equipment such as flap we can open the furnace temperature control on the hydraulic picture, see if hydraulic automatic shutdown, whether the liquid level in a low level, if this is the case, you need to find the corresponding hydraulic pump hydraulic station of furnace bottom and the top-level ruler, liquid level feet above has the scale and the highest level, the lowest level of the limit switch, when the liquid level is not the lowest and highest level between the hydraulic pump will automatically shut down, if discover the level is too low to the lowest level limit switches to put down a, as long as no less than the minimum requirements of hydraulic pump work can be.

92. What should I pay attention to when controlling temperature?

1. Furnace temperature should be controlled accurately. If the temperature jump is large you need to control the gas flow at a certain value, hit the manual.

2. Pay attention to the temperature trend when empty of the furnace. Because no matter how high the temperature rises after the manual operation, the gas will only keep the set flow rate unchanged, which will lead to a sharp rise in temperature.

3. When the temperature is controlled, the gas will be played to manually adjust the amount of gas when the air will move, in turn, to adjust the flow of air, the gas flow will fluctuate. The only way to fix the gas flow rate is to manually pump the gas.

4. The computer screen shows the pressure control of the gas pipeline. If the button cannot be turned off, it will not be changed in any place.

5. When the temperature is controlled, if the gas is turned on to the maximum but still cannot increase the furnace temperature, then the gas pressure should be increased to increase the gas flow to reach the required value.

6. The furnace temperature curve is large to the range of waves. What we need to do is to control the lowest and highest values of this curve within the allowable temperature deviation.

7. When the furnace is closed, the temperature control screen should be manually played before any other operation.

8. Each thermocouple has two pieces of AB. The temperature shown on the screen is the average temperature of the two thermocouples when there are two

A thermocouple temperature difference of 3 degrees will alarm. If one thermocouple is broken you can switch to the other and report it for repair.

93. What is the function of the hot air release valve?

One of the functions of the hot air release valve of the quenching furnace is to play the role of an anti-surge valve to prevent air surge injury and combustion fans.

Another role is to reduce the furnace temperature, in the empty furnace can open the hot air release valve. Dissipating hot air to maintain the furnace temperature without temperature fluctuations caused by an empty furnace. The return furnace pressure valve and furnace pressure valve, respectively in the heating section and the soaking section, can adjust the pressure of the furnace to adjust the temperature.

In order to protect the heat exchanger from burning out due to high temperature, the flue gas is equipped with thermocouple temperature measurement, the temperature exceeds 800℃, and its regulator output is used to control the opening of the outlet valve of the diluent fan. If the temperature rises too high, the opening will increase, adding more cold air to protect the heat exchanger. Temperature below 800℃, due to the large fan capacity, according to experience output a fixed opening to prevent surge.

94. What is the function of the air preheater on the quenching furnace?

1. In front of the air preheater, the flue is provided with an air inlet pipe and a cut-off valve. When the flue gas exceeds 850 ℃ (adjustable), the regulating valve will be opened automatically, and the cold air will be absorbed and released by chimney suction to reduce the flue gas temperature.

2. The hot air pipe behind the air preheater is equipped with an automatic hot air release valve. When the air temperature exceeds 500 ℃ (adjustable), the release valve will be opened automatically to reduce the air temperature.

95.How to control the furnace temperature in the production process?

In the normal production process, the furnace temperature is constantly changing, because there are many factors that affect the temperature of the furnace. For example, the action of the stepping beam, the rise, and fall of the stepping beam will change the pressure in the furnace, thus changing the temperature of the furnace. The quenching furnace USES the opening of the flue gate to adjust the furnace pressure, and the return furnace USES two furnace pressure regulating valves to control the furnace pressure.

There is also the bottom water seal groove, if the water inlet pipe stops feeding, the water temperature in the water seal groove will continue to rise, the water temperature is too high, the water will evaporate, thus affecting the temperature in the furnace and the quality of steel pipe.

Quenchback furnace each section USES two thermocouples to measure temperature, choose one as the output signal, and the role of another thermocouple has two points: 1, for the other thermocouple damaged after preparation.2.When the temperature difference between the two thermocouples is 3 degrees, the furnace temperature control screen will automatically alarm.

96. How to control the furnace temperature while stewing?

If the furnace time is less than 30 minutes, the furnace temperature should be lowered by 10 degrees Celsius. After the end of the furnace, the correction team should be informed to sample the pipe materials in a separate group. When the time is more than 30 minutes, the furnace temperature should be lowered by 20 degrees and the production should be reorganized.

Quench furnace closing time less than 15 minutes do not do abnormal treatment, more than 15 minutes can be directly out of the furnace pipe to the no. 2 cold bed, such as troubleshooting after the pipe on the cold bed will be collected on the quenching furnace feeding bench to deal with again. Because of the longer duration of the boring furnace, furnace tubes heat absorption ability is more and more small, the furnace temperature will rise obviously, at this time in advance to furnace temperature down, don’t wait to furnace temperature rise up again, want to go down is not easy, and we can reduce the pressure in the furnace, increasing heat radiation opening, to reduce the effect of furnace temperature.

97. What should I pay attention to when controlling temperature?

Usually in the control of furnace temperature need to pay attention to two points: one is to observe the trend of furnace temperature change, the purpose is to step on the brakes in advance.

Second, when the furnace temperature is found to be abnormal, we should observe the furnace pipe into the furnace. If the pipe does not enter the furnace in time due to the bad turning signal of the feeding platform, and the front pipe is empty out a space of three or four feet, when the furnace temperature is on the rise, if the temperature is not handled, it will dropdown. If we lower the temperature in advance, it may drop too much, and we will have to heat up again, which is not worth the loss. Therefore, the above two points should be combined in the normal production process.

After changing the specifications, the furnace temperature needs to increase 40 to 50 degrees, at this time is the critical moment of furnace temperature control, can’t temperature too fast, if the raw coal gas valve position at 30%, in order to speed up the heating rate, the valve position to 100%, which will cause a straight drop in gas pressure, may eventually cause the safety valve automatically fall, resulting in production accidents. There is also a sudden change in the air valve position will cause fan surge. When the temperature is raised by adjusting the set temperature, the one-time rise shall not be more than 10 degrees. After the temperature is stabilized, the coal gas valve position shall not exceed 60%.

When the temperature rises to the temperature required by the process, the temperature cannot be stopped, because the temperature shown by the instrument at the beginning is not the actual temperature in the furnace, but the temperature of the thermocouple and the temperature of the stepping beam is not reached. So we need to continue to raise the temperature to seven or eight or even ten degrees above the desired temperature so that the temperature throughout the furnace is uniform and stable.

If continuous production diameter steel tube, the larger specifications due to large heat, the temperature will drop sharply, especially the temperature of the heating period is not easy to control, even if the gas valve to 100%, 80% air (stove temperature increased maximum limit), also can’t control the furnace temperature, at this time, should stop feeding, such as walking beam empty out after four or five feet, temperature rise after the feed again.

98. Why can’t the heating rate be too fast?

If the heating speed is too fast, the gas pressure will drop quickly resulting in the safety valve falling, in addition, the heating speed is too fast on the refractory impact is not good, reduce the life, serious will cause resistance to material cracking.

99.What kinds of cooling methods are there?

1. Adjust the setpoint

If the temperature is slightly higher than the set value, just lower the set value and return to the original set value when the temperature is close to the process value.

2. Reduce the gas flow

If the furnace temperature drops soon, turn on the gas flow manually.When the temperature rises, gradually reduce the gas flow, so that the temperature reached the set value when there is just the right flow, such as the furnace temperature stability after automatic play.

3. Adjust the furnace pressure

If the temperature of the furnace rises very high and the gas output is already 0, in order to reduce the temperature of the furnace as soon as possible, it is necessary to open the pressure valve of the furnace to output heat dissipation, and then return to the original position after the temperature is restored

4. Turn up the airflow

If the temperature of the furnace rises sharply, gas and air can be played manually to increase the airflow. If the air is too big to kill the burner, temporarily do not burn the burner until the temperature drops and then go to burn the burner.

100. Why does water quench Wheaton stop motionless in mid-air?

What is it and the solution?

1. The metal induction signal sensitivity of the water quenching proximity switch is too high, and the time for the rotation of the water quenching Sveden lever is controlled within 10 seconds, which is not enough.

2. At this time, Swindon just received a feed signal, halfway up, the metal sensor left its original position, causing the proximity switch to receive the signal ahead of time.

3. When the Swinton lever stops at the base position, the approach switch is directly opposite the metal sensor. The Swinton lever will stop only when it is facing the base position.

Solutions:

1. Rotate the Swindon lever once each time, lift the steel tube on the roll table, put it on the water quenching wheel, and then return to the initial position. Keep the rotation time under 10 seconds.

2. The position of the metal sensor needs to be adjusted to the base position.

3. If such faults occur frequently, report to the equipment for repair. The metal induction can be fixed to prevent it from shifting.

How to solve the problem of pipe stuck between quenching wheel and moving door during water quenching?

Causes:

1. The pipe is too bent and cannot be pressed by the pressing wheel. When water quenching is sprayed inside and outside, the pipe shakes too much on the quenching wheel, causing the pipe to roll out of its original position and into the space between the quenching wheel and the moving door.

2. During water quenching, the pipe is thrown out of the quenching wheel, which gets stuck between the moving door and quenching wheel and causes the pipe to bend.

Treatment method:

In the event of such a failure, the furnace roll will be manually driven, the feeding bench into the furnace roll stop feeding. Then inform the train to lift the pipe out, the wire rope should be crossed when hanging, so that when lifting, the wire rope is not easy to hang to the equipment, at the same time improve the efficiency of fault handling.

101. What is the cause of multiple pipes being turned over to the quenching furnace before being put into the roller table?

The reason:

1. Stack pipes when discharging

2. The pipe cannot be sensed on the pipe bending roller table, and the sheet continues to turn the pipe

3. Bad signal of entering roller table

Solutions:

1. Manually enter the furnace to separate the steel tubes

2. Adjust the signal and wipe the signaler on site

102. How to solve the problem that the steel pipe does not move after entering the furnace?

The reason:

1. The tube whose position deviation of the infrared grating cannot reach the correct position

2. The grating reflector is covered with dust

3. The pipe is bent, and the grating cannot be seen

4, hydraulic pump jump, a hydraulic cylinder has broken (translation cylinder screw, lifting cylinder sealing ring)

Solutions:

1. Raster position needs to be adjusted (slight action)

2. Wipe the grating into the furnace

3, the bottom grating to use the “retractable” wiper wipe

4. Open the pump on the temperature control screen and inform the equipment party to replace and maintain

103. What abnormalities may occur before the furnace enters the furnace?

1. The pipe fell into the furnace when it turned over

2. The knock over signal is not in place

3. Pipe bend signal cannot be sensed

4. Abnormal surface quality of steel pipe caused by flap wear

5. The drag zipper breaks or the motor is broken

In case of any of the above cases, the site inspection and maintenance shall be reported immediately.

104. What are the precautions for mixing steel?

1. The inspection team shall correct the receiving basket, and the staff shall strictly and carefully confirm and check the count on the label before receiving the material. At the same time, they shall distinguish the furnace number and batch number. Timely information maintenance should be done after the pipe is bundled into storage. In addition, the operation of DNT flaw detection feeding and receiving is the same as above;

2. When receiving and printing labels, it is necessary to ensure that the count on each pipe bundle label is the same as the actual count; As the number on the label is different from the actual number due to the situation of pipe scrapping, etc., the pipe material information must be recalled and reprinted. Handwritten correction on the label is strictly prohibited.

3. Check and explain the input and output of pipe materials every month, and explain the rework in stock. Therefore, at the end of each furnace number, each shift must check whether the input and output are accurate. The middle shift on the last day of each month must check the input and output of that month.

4. The furnace team (Baosteel is the material receiver of the straightener) is responsible for marking the first three pipe ends (west end) of each furnace number on the rear cooling bed of the straightener, so as to facilitate the material receiver to distinguish the pipe materials of the front and rear furnace Numbers according to the marking;

5. Only when there is no previous furnace number tube material on the cold bed in front of the straightener, the tempering shift shall be informed 10 minutes before the new furnace number tube material comes out;

6. After the label is printed, the moderator shall check whether the message has been successfully sent to MES in time. If it has not been successfully sent, the moderator shall send the message in time;

7. The interval time for the production of pipe materials with the same specification and different furnace Numbers shall not be less than 10 minutes;

105. Why should the equipment be inspected?

Prior to production, on-site equipment must be confirmed. If there is any abnormal condition, the site inspection and treatment shall be notified in time. It is strictly prohibited to work with diseased equipment. During the production process, the above items shall also be checked after the shift. If there is any abnormality, which affects the final product quality, the production shall be suspended and the chief operator and engineer shall be informed in time. We will not start production until the problem has been solved.

106. What items are checked in the water quenching equipment?

1. Whether the external spray baffle, Swindon, rotating supporting wheel, moving door, and pressing wheel operate normally

2. Whether the specifications of the inner nozzle and the press wheel are installed correctly

3. Whether the internal and external water spraying quantity meets the requirements, whether the external water spraying is uniform, and whether there is a blocking phenomenon. If there is a blocking phenomenon, the production can be organized only after the water flow is cleared to ensure unobstructed.

4. Whether the grating and the signal with or without material are working normally

107. What items are inspected in the heat treatment furnace?

1. Whether the mechanical equipment inside and outside the furnace operates normally

2. Whether the grating and the signal with or without material are working normally

3. Whether the furnace temperature is normal (use the thermometer to measure the temperature inside the furnace before each production, and inform the engineer in time if the out-of-tolerance with the set temperature is greater than 15℃)

108. How to achieve quality control?

1. Before production, the on-duty personnel shall first check the quality and technological parameters of the contract to be produced through the MES system, and set relevant equipment according to requirements. If MES system fails, please refer to Annex I (heat treatment technological parameters) for setting, and timely inform the engineer in charge.

2. In case of shutdown due to equipment failure, the input of single machine and whole line shutdown records shall be completed on L3 in a timely manner.

3. Strengthen the inspection of the first ten steel pipes produced after the specification exchange, timely report to the chief operator or engineer in charge if there is any abnormality, and register it on the post record.

4. In the production process, the appearance and quality of products should be inspected. If there is any abnormal situation, it should be recorded on the post record and reported to the chief of operation or the engineer in charge.

5. Monitor the temperature of the quenching and tempering furnace to ensure that the furnace temperature is controlled within the required range. If the short term out-of-tolerance (less than 15 minutes) and the temperature out-of-tolerance does not exceed 10℃, the personnel of the rectification shift shall be informed to conduct a separate batch of the pipe materials in a timely manner, and the batch shall be registered in the post record. If the equipment failure cannot be solved in a short period of time, the temperature out-of-tolerance time exceeding 15 minutes shall be effectively isolated for the batch of pipe materials and the production shall be reorganized, and the registration shall be made on the position record.

6. The staff on duty should carefully register the post records to ensure the registration information is accurate and clearly distinguishable. If there is any alteration, it must be signed and confirmed by the alternator.

7. After the production of a furnace number, it is necessary to check the feed flow information of the furnace number, and then put the next furnace number after the verification is correct.

8. The monitor shall check the books in the intermediate warehouse and sign for confirmation before leaving the office. In case of any discrepancy between the physical object and the standing book or computer information, it shall be dealt with in a timely manner or indicate the reason before leaving the post.

9. The pipe material with unqualified performance shall be separated from the normal production pipe material, and the heat treatment shall be conducted again in a separate batch.

109. What are the principles of material flow control?

1. Responsible for tracking the pipe material of each furnace number in the production process, confirming the count of input, the number of output, and the actual number of MES to check, and tracing the nonconformity to determine the cause of nonconformity.

2. Responsible for the supervision of casing and flaw detection feeding, and it is absolutely prohibited to throw pipe materials whose test batch performance cannot be confirmed into the casing line.

3. Responsible for the maintenance of the information of the intermediate warehouse and supervision of the personnel responsible for the operation of the intermediate warehouse. Strictly prohibit the warehousing of pipe materials without incoming material information, and confirm the entry account of the intermediate warehouse after the shift.

110. What are the specific duties of a heat treatment worker?

1. When the furnace is feeding, the feeding must be carried out according to the furnace number. After one furnace number is finished, the other furnace number can be cast. The interval between each furnace number shall be at least 10 minutes and the quenching furnace shall be at least half empty when changing specifications.

2. The furnace shift shall mark the first three steel tubes of each furnace number and notify the rectification shift 10 minutes before the new steel tubes of the furnace number come out of the furnace. According to the mark on the pipe, the leveling shift shall separate the front and rear furnace Numbers from the gap, and also make a clear mark on the pipe, so that the receiving personnel can distinguish the front and rear furnace Numbers to collect materials according to the mark.

3. In order to ensure that the actual count of each furnace number is consistent with the feeding information, the material staff in the furnace class shall make a list of the actual count of each pipe material going up to the feeding platform. If the actual count is not consistent with the number on the label, the actual count shall be indicated on the label; The furnace shift operator should clear the counter at the furnace outlet in time after the last furnace number comes out of the quenching furnace. After the last tube of this furnace number comes out, check whether the counter count is consistent with the feeding information of this furnace number. If not, the information should be filled in the post record on the shift, and inform the correction shift in time.

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