A surface hardness control method and production method for large-size cutting non-quenched round steel

By controlling the residual heat of hot-rolled round steel and using surface induction heating technology, the surface microstructure of large-size non-quenched and tempered steel is transformed into pearlite and ferrite, solving the problem of excessive surface hardness and achieving improved cutting performance and reduced energy consumption.

CN122405947APending Publication Date: 2026-07-17JIANGSU LIANFENG ENERGY EQUIP +1

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
JIANGSU LIANFENG ENERGY EQUIP
Filing Date
2026-06-10
Publication Date
2026-07-17

AI Technical Summary

Technical Problem

Excessive surface hardness in large-scale machining of non-quenched and tempered steel leads to accelerated tool wear and reduced machining efficiency, and existing stress-relief annealing methods have limited effectiveness.

Method used

By utilizing the residual heat of hot-rolled round steel to control the surface reddening temperature and surface induction heating process, the surface layer is austenitized through induction heating and then air-cooled to a pearlitic and ferritic structure, thereby reducing the surface hardness.

Benefits of technology

It effectively reduces surface hardness to 250~300HBW, improves machinability, and maintains the mechanical properties of the material while reducing energy consumption.

✦ Generated by Eureka AI based on patent content.

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Abstract

本发明涉及金属材料热处理技术领域,具体涉及一种大规格切削非调质圆钢的表面硬度控制方法及生产方法,所述控制方法是先利用热轧圆钢穿水冷却后的余热控制圆钢表面返红温度为500~600℃,心部温度≥600℃,之后进行表面感应加热将圆钢表层加热至奥氏体化温度,使表层组织奥氏体化,然后空冷至300~400℃,使表层奥氏体转变为珠光体与铁素体组织。本发明利用热轧圆钢穿水冷却后的余热,结合表面感应加热工艺,通过余热‑感应协同机制,降低大规格切削非调质钢表面硬度,使表层硬度降到250~300HBW,从而改善切削加工性能。
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