Effect of Ti and B microadditions on the hot ductility behavior of a High-Mn austenitic Fe-23Mn-1.5Al-1.3Si-0.5C TWIP steel
Effect of Ti and B microadditions on the hot ductility behavior of a High-Mn austenitic Fe-23Mn-1.5Al-1.3Si-0.5C TWIP steel
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DOI：
10.1016/j.msea.2015.09.079
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发表时间：
2015-11-11
期刊：
影响因子：
6.4
通讯作者：
Cabrera, J. M.
中科院分区：
文献类型：
--
作者：
Mejia, I.;Salas-Reyes, A. E.;Cabrera, J. M.
本文研究了Ti和B的复合添加以及凝固路线对高Mn奥氏体孪晶诱导塑性钢热塑性行为的影响。为此，在700和1100摄氏度之间的不同温度下，在10（-3）s（-1）的恒定应变速率下进行单轴热拉伸试验。通过测量试样断裂后的横向面积减少（%RA）来确定热延展性。通过SEM-EBSD和TEM技术进行表征，以确定微观结构特征和开裂现象之间的关系。结果表明，在中温区（800-900 ℃）早期发生动态再结晶（DRX）是提高塑性的有利机制，RA值可达82%。这些高RA值进行了讨论，通过非平衡偏析和Ti（C，N）沉淀，减少有害的沉淀物，如BN和AIN的形成的晶界凝聚力的改善硼的效果。此外，鉴定了Fe-23（B，C）（6）和B4 C化合物，它们对热延展性的危害小于氮化硼化合物。最后，在最高延展性的温度范围内的本发明的马氏体钢的断裂表面表明，失效模式是韧性类型的，如由许多韧窝的存在所证明的。(C)2015 Elsevier B. V.版权所有。
This research work studies the effect of combined Ti and B microadditions and the solidification route on the hot ductility behavior of a high-Mn austenitic Twinning Induced Plasticity (TWIP) steel. For this purpose, uniaxial hot tensile tests were carried out at different temperatures between 700 and 1100 degrees C under a constant strain rate of 10(-3) s(-1). The hot ductility was determined by measuring the reduction of transverse area (%RA) after specimen rupture. Characterization was performed by SEM-EBSD and TEM techniques in order to identify the relationship between microstructural features and cracking phenomena. Results indicate that the early occurrence of dynamic recrystallization (DRX) at the intermediate temperature range (800-900 degrees C) is the favorable mechanism that enhances the ductility, achieving RA values up to 82%. These high RA values are discussed in terms of the boron effect on the improvement of the grain-boundaries cohesion through non-equilibrium segregation, and Ti(C,N) precipitation, which reduces the formation of harmful precipitates such as BN and AIN. Additionally, the Fe-23(B,C)(6) and B4C compounds were identified, which are less detrimental to hot ductility than boron-nitride compounds. Finally, the fracture surfaces of the present TWIP steels in the temperature range of the highest ductility indicate that the failure mode is of the ductile type as evidenced by the presence of many dimples. (C) 2015 Elsevier B.V. All rights reserved.