Application Specific Microstructure Development in Microalloyed Bainitic Hot Strip
Application Specific Microstructure Development in Microalloyed Bainitic Hot Strip
复制标题
DOI：
10.4028/www.scientific.net/msf.949.76
复制
发表时间：
2019-03
期刊：
影响因子：
--
通讯作者：
M. Menzel;Anastasia Höhne;Gerhard Gevelmann;A. Tomitz;U. Prahl;W. Bleck
中科院分区：
文献类型：
--
作者：
M. Menzel;Anastasia Höhne;Gerhard Gevelmann;A. Tomitz;U. Prahl;W. Bleck
在贝氏体钢的热轧过程中，必须将时间和温度控制在较窄的范围内，以避免不期望的铁素体或马氏体相分数。为了设计生产贝氏体钢的可靠工艺窗口，研究了不同工艺参数对微合金化和非微合金化贝氏体钢的相变和最终性能的影响。通过热机械试验，分析了其对力学性能、强度和韧性的影响，并可制作二次试样。透射电子显微镜（TEM）和电子探针显微分析（EPMA）被用来调查的不同属性的起源。特别地，已经发现微合金钢的热机械轧制导致强度的提高。这部分是由于转变动力学和部分应变诱导沉淀。此外，硬化行为受到通过冷却策略配置的贝氏体基体内的第二相的影响。粗马氏体/奥氏体（MA）结构降低韧性，而细分散的MA岛增加硬化潜力。此外，从材料实验的结果被用来开发一个速率模型与形核模型相结合，以预测相变的动力学和贝氏体显微组织的形状。
During the hot rolling of bainitic steels, time and temperature must be controlled within narrow limits to avoid undesirable ferritic or martensitic phase fractions. In order to design a reliable process window for the production of bainitic steels, the effects of the different process parameters on the phase transformation and the final properties of a microalloyed and a non-microalloyed steel were investigated. Thermomechanical tests with the possibility of producing secondary samples were conducted to analyze the influence on the mechanical properties strength and toughness. Transmission electron microscopy (TEM) and electron probe micro analysis (EPMA) were used to investigate the origin of the differing properties. In particular, it has been found that thermomechanical rolling of the microalloyed steel leads to an improvement in strength. This is partly due to the transformation kinetics and partly to strain-induced precipitations. Further, the hardening behavior is affected by the secondary phase within the bainitic matrix configured through the cooling strategy. Coarse Martensite/Austenite (MA) structures reduce toughness, whereas finely dispersed MA islands increase the hardening potential. Furthermore, the results from the material experiments were used to develop a rate model in combination with a nucleation model to predict the kinetics of the phase transformation and the shape of the bainitic microstructure.