Pipe Induction Heating Equipment / System / Machine — Complete Induction Quenching & Tempering Process Solution
1. Project Overview & Application Scope
This induction heating quenching and tempering solution is specially designed for
seamless steel pipe, welded steel pipe, oil casing, OCTG pipe, hydraulic support pipe, engineering machinery thick-walled pipe. Adopt full-line continuous online induction heating process, match Forever electromechanical
medium frequency IGBT heating power supply, realize one-stop automatic quenching + tempering integrated production. It effectively improves pipe yield strength, tensile strength, impact toughness and straightness, fully meets API, GB and international engineering standard requirements, suitable for mass production 24-hour non-stop industrial heavy-duty workshop.
Applicable pipe specifications: outer diameter Φ20mm–Φ530mm；wall thickness 3mm–40mm；pipe length 2m–18m；carbon steel, alloy structural steel, low-alloy high-strength steel.
2. Core Process Principle of Pipe Induction Quenching & Tempering
Different from traditional furnace heat treatment, pipe induction heating system uses medium-frequency electromagnetic eddy current rapid heating. Fast heating speed, short temperature holding time, fine grain metallographic structure, no oxidation and no decarburization on pipe surface. The whole line adopts rotary forward feeding + circumferential uniform heating + closed-loop infrared constant temperature control to ensure uniform temperature inside and outside the pipe wall, no soft spots, no bending deformation, stable hardness consistency.
Two-step core process：First, rapid induction austenitizing heating + high-pressure uniform spraying quenching → second, low-temperature induction uniform tempering + slow cooling shaping → finished pipe with stable mechanical properties.
Pipe induction heat treatment machine
3. Complete Composition of Forever Pipe Induction Heating System
The whole set of equipment is integrated and matched by Forever electromechanical, plug-and-play, no secondary transformation required on site.
Medium-frequency induction heating power supply (core heart): dedicated parallel resonant IGBT digital power supply, strong anti-grid fluctuation ability, constant power output, suitable for long-term continuous pipe heating.
Special multi-section split induction coil for pipes: oxygen-free copper tube winding, fully water-cooled structure, uniform circumferential magnetic field, ensuring no temperature difference between inner and outer wall of thick-walled pipe.
Automatic rotary roller conveying system: helical angle anti-deviation design, pipe rotates synchronously while moving forward, heating more uniform, effectively controlling pipe bending.
High-pressure sealed ring quenching unit: annular uniform water spray, adjustable water pressure and flow, no local hardening crack, stable quenching hardness.
Infrared real-time temperature closed-loop control system: real-time monitoring of heating temperature before quenching and tempering temperature, automatic power adjustment, temperature accuracy ±5℃.
Closed circulating water cooling station + electrical control cabinet: ensure power supply, coil and quenching water supply stable all day long.
Post-tempering slow cooling straightening rack: reduce internal stress, ensure finished pipe straightness within standard tolerance.
4. Standard Induction Quenching & Tempering Process Flow (On-site Direct Execution)
Step 1: Automatic feeding and centering positioning — The raw steel pipes are automatically arranged and fed one by one, the roller automatically centers to prevent eccentricity, ready to enter the heating area.
Step 2: Medium-frequency rapid quenching heating — The pipe passes through the first-stage multi-section induction coil, quickly heated to quenching temperature 880–930℃ according to steel grade. The inside and outside of the pipe wall are heated synchronously, no cold core, no overheating on surface.
Step 3: High-pressure uniform ring spraying quenching — Immediately after reaching the temperature, enter the quenching station for 360° all-round uniform water cooling. The metallographic structure is transformed into uniform martensite, improving pipe hardness and wear resistance.
Step 4: Online continuous induction tempering heating — After quenching, directly enter the second induction heating area for low-temperature tempering at 520–650℃. Eliminate quenching internal stress, improve toughness, prevent cracking.
Step 5: Constant temperature heat preservation + slow cooling shaping — After tempering, pass through the heat preservation slow cooling area to stabilize the structure, effectively avoid pipe bending and deformation.
Step 6: Automatic discharging + hardness sampling inspection — Finished pipes are automatically discharged and stacked. Random hardness and tensile test, all mechanical indicators meet standard requirements.
5. Key Parameter Matching Standard (Forever On-site Commissioning Standard)
Heating frequency selection: thick-walled large-diameter pipe adopts low frequency 500Hz–2kHz；thin-walled small-diameter pipe adopts medium frequency 2kHz–8kHz, ensure uniform penetration heating of pipe wall.
Power matching principle: match power according to pipe outer diameter + wall thickness + production speed. Forever power supply supports one-key adaptive frequency conversion, no need to replace hardware.
Quenching water pressure control: conventional steel pipe 0.25–0.4MPa；alloy high-strength pipe 0.4–0.6MPa, avoid quenching soft band and cracking.
Temperature control tolerance: quenching temperature error ≤±5℃；tempering temperature error ≤±8℃, ensure consistent batch performance.
pipe induction heat treatment equipment
6. Common On-site Problems & Forever Standard Solutions
Problem 1: Pipe hardness uneven, local soft spots after tempering — Reason: coil magnetic field uneven, conveying speed unstable. Solution: replace high-precision integral coil, use servo synchronous frequency conversion feeding, optimize temperature closed-loop parameters.
Problem 2: Pipe bending and deformation after heat treatment — Reason: one-sided heating, uneven quenching water volume. Solution: full rotary synchronous conveying + 360° annular uniform water spray, match slow cooling straightening process.
Problem 3: Low output, power cannot run up, high power consumption — Reason: power supply and coil impedance mismatched, power factor low. Solution: Forever technical team calibrates resonance parameters on site, power factor raised above 0.95, energy saving and high efficiency.
Problem 4: Pipe surface oxidation serious, poor appearance — Reason: heating holding time too long. Solution: induction rapid heating, shorten high-temperature residence time, keep pipe surface smooth and clean.
7. Equipment & Process Core Advantages (Forever Electromechanical)
1. Special medium-frequency power supply for pipe induction tempering, heavy-duty design, 24-hour stable operation, low failure rate.
2. Integrated full-line automation, one person can operate the whole line, save labor cost greatly.
3. Uniform heating inside and outside, small deformation, stable mechanical performance, high finished product rate.
4. Energy-saving induction heating, lower power consumption than traditional furnace, high production efficiency.
5. Free process trial heating, free on-site installation and commissioning, global remote after-sales service support.
8. Application Finished Pipe Delivery Standard
After treatment by this pipe induction heating tempering system: stable hardness, uniform metallographic structure, qualified tensile and impact resistance, straightness meets engineering requirements, no cracking, no oxidation, fully suitable for petroleum casing, hydraulic engineering, bridge machinery, high-pressure pipeline supporting projects.
