低碳鋼線退火時晶粒粗大之防止

Prevention of Abnormal Grain Growth in Annealing Low-Carbon Steel Wires

呂南雄(Lu Nan-Hsiung)

《鑛冶：中國鑛冶工程學會會刊》 30卷4期 (1986/12) Pp. 100-107

https://doi.org/10.30069/MM.198612_30(4).0012

摘要

1.低碳鋁脫氧鋼之線材，經冷抽後作軟化退火，因退火時鋼線發生肥粒鐵異常粗大之現象，導致後續之冷加工困難。2.當退火前冷抽率低於20%時，發生晶粒粗大之原因係冷抽率不足，致使退火時，再結晶較為困難，晶粒成長速率極大於成核速率，而造成晶粒粗大；提高退火前之冷抽率至24%以上，將可防止此種晶粒粗大之間題。3.當退火前冷抽率高於90%時，發生晶粒粗大之原因係退火時對晶粒成長之抑制力降低所致；提高線材的AI/N之比值，使退火時，所析出之AIN穩定，相對地晶粒成長過程亦將較穩定，而可有效地防止晶粒粗大之問題。

並列摘要

Abnormal grain growth in low-carbon Al-killed steel wires occurs during annealing after cold drawing. It reduces the ductility of wires and degrades properties needed for subsequent cold work. When drawing reduction before annealing is below 20% coarse-grain growth will occur in During annealing. The rate of growth is more rapid than that of nucleation, this will easily lead to abnormal coarse grain. Increasing the drawing reduction to more than 24% will prevent the problem mentioned above. When drawing reduction is more than 90%, abnormal grain growth occurs again. This is caused by decrease of the restraining force on grain growth during annealing. With a high Al/N ratio in steel wires, AIN particles are stabilized and grain growth is normal during annealing. So it is very effective to increase Al/N ratio to prevent the abnormal grain growth at high drawing reduction.