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Rebar steel induction heat treatment process#

Aug. 06, 2026

Rebar steel induction heat treatment process

Brief Introduction

Rebar induction heat treatment machine is a continuous online quenching & tempering (Q&T) technology for ribbed reinforcing bars, built on electromagnetic‑induction principle. Eddy current generates inside rebar to achieve rapid heating, followed by water spray quenching and induction tempering. It produces high‑strength construction rebar with hard surface and tough core, widely used for high‑rise buildings, bridges and pre‑stressed concrete components。

Core Process Flow

1.Feeding & Straightening

Rebar is fed continuously, straightened and surface cleaned before entering heating station.

2.Induction Austenitizing (Quenching Heating)Rebar passes through intermediate‑frequency induction coils, rapidly heated to 850‑950 ℃ for austenite transformation. Heating time depends on bar diameter, normally 5‑15 seconds. Medium frequency for large‑size rebar; higher frequency for small‑diameter bars.

3.Online Water QuenchingHigh‑pressure water spray instantly cools rebar surface. Surface layer transforms into hard martensite, while bar core remains ferrite‑pearlite with good toughness. Controlled cooling rate avoids cracking.

4.Induction TemperingRe‑heat quenched rebar to 400‑650 ℃ by independent induction power supply to release quenching residual stress, improve ductility and avoid brittleness. Air cooling or soft spray cooling after tempering.

5.Cooling, Inspection & DischargingFinal air cooling; online monitoring for temperature, hardness and dimension; finished rebar cut‑to‑length and discharged.

Typical Process Parameters

Quenching heating temperature: 850‑950 ℃
Tempering temperature: 400‑650 ℃
Line speed: adjustable according to rebar φ6‑φ40 mm
Power source: IGBT energy efficient induction power supply
Metallurgical structure: surface martensite layer + tough ferrite‑pearlite core

Main Advantages

✅ Ultra‑fast heating, low oxidation & decarburization

✅ Small thermal deformation, stable mechanical performance

✅ Continuous online production, high throughput

✅ Energy‑saving & eco‑friendly, easy PLC automatic control

✅ Adjustable strength grade for different rebar specifications

Rebar steel induction heat treatment process

Overseas manager:Mr. Wang

Email:tom@foreverfurnace.com

Phone/Wechat/Whatsapp:+8613303078975

Next: Pipe Induction Hardening & Tempering System