铌微合金化高碳钢的连续冷却转变.pdf

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第16卷第3期
钢铁研究学报
Vol 16, No. 3
2004年6月
JOURNAL OF IRON AND STEEL RESEARCH
Jun.2004
铌微合金化高碳钢的连续冷却转变
李
康永林1,顾克井2,魏军2,陈银莉,蔡开科2
(1.北京科技大学材料学院,北京100083;2.北京科技大学治金学院,北京100083)
摘要:在 Geeble-1500热/力模拟试验机上测定了铌微合金化高碳钢与普通高碳钢变形后的连续
冷却转变曲线,分析比较了它们的组织演变规律。实验结果表明,与普通高碳钢相比,含铌高碳钢
的转变温度较高,A十P两相区的温度范较大(在所测定的冷速下,温度范围均在100℃以上),
且在相同冷速下,先共析铁素体的数量明显增多,而奥氏体晶粒较小。在本实验条件下,当冷速大
于10℃/s时,含铌高碳钢转变后的珠光体片层间距较小;在冷速大于30℃/s时,其基体中出现贝
氏体组织。
关键词:铌;微合金化;冷却速度;先共析铁素体;高碳钢
中图分类号:TG142.3文献标识码:A文章编号:1001-0963(2004)03-0044-05
Continuous Cooling Transformation of Niobium Microalloyed
High Carbon Steels
LI Xiang KANG Yong-lin GU Ke-jing, WEI Jun, CHEN Yin-li, CAI Kai-ke2
(1, 2. University of Science and Technology Beijing, Beijing 100083, China)
Abstract: The transforrnation of deformed niobium-microalloyed high carbon steel and plain high car-
bon steel during continuous cooling process were simulated on Gleeble-1500 thermomechanical simu
lator, and the microstructure evolution of these steels were analyzed and compared. The experimen
tal results compared with plain showed that the niobiur-rraicroalloyed high carbon steel has high car.
bon steel higher transformation temperature and wider temperature range of dual-phase region(A+
P), which is more than 100 C at different controlled cooling rate. Cooled down at the same rate a
plain high carbon steel, in the microstructure of niobiur-microalloyed high carbon steel there is
much more proeutectoid ferrite, with much finer grain size, and the pearlite interlamellar spacing is
thinner when the cooling rate is higher than 10 C/s. In addition, the bainite is occurred when cool
ing rate is higher than 30 C/s
Key words: niobium; micro-alloying; cooling rate; proeutectoid ferrite high carbon steel
高碳钢线材是生产制绳用髙强度钢丝的重要原组织性能的初步研究上应用效果比较明显,材料性
材料。国内生产的高碳钢线材普遍存在抗拉强度能有所提高2。钢中加入铌能显著提高奥氏体的
低、塑韧性差、拉拔过程中容易脆断等问题,而钢的粗化温度和再结晶温度,具有细化奥氏体晶粒和弥
微合金化是提高线材强度并保持良好塑性和初性的散强化的作用,其中以奥氏体晶粒细化的作用最为
条有效途径。
显著。而奥氏体晶粒细化能在提髙强度的同时保
目前,铌元素微合金化在线材生产中的应用较持良好的塑韧性。在高速线材生产中,控冷工艺对
相关的基础研究不多,大多集中在对线材实物的铌微合金化作用的发挥有着决定性的影响。鉴于目
基金项目:国家自然科学基金资助项目(50334010)
作者简介:李翔(1977-),男,硕上;收稿日期:2002-11-13;修订日期:2003-04-01
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