复杂贝氏体组织和性能的定量关系研究(一)  

Quantitative Investigation on Microstructure and Properties of Complex Bainite(1)

作　　者：朱祖昌[1] 杨弋涛[2] 齐兴[2] 曹静[2] 

机构地区：[1]上海工程技术大学,上海201620 [2]上海大学,上海200072

出　　处：《热处理技术与装备》2017年第3期65-70,共6页Heat Treatment Technology and Equipment

摘　　要：钢中的贝氏体组织能提供强度和韧度的很好匹配,因而现在已引起人们的青睐。贝氏体组织的这种又强又韧的特性起自于其超细贝氏体铁素体以及内部析出细微第二相。工业贝氏体钢经过化学成分和加工工艺参数的优化,可以省略其后的热处理过程,从而能获得大的经济效益。Zajac等^([1])选定和生产具有4种贝氏体类型的16种钢,含碳量范围为0.06%~1.0%,能处理获得单一和复杂的贝氏体组织。他们把CCT和TTT图用于膨胀的仪测定,以次确定合适的热处理工艺,得到全贝氏体组织,并对试样进行拉伸和冲击测试。采用高分辨SEM和背散射电子衍射(EBSD)分析技术获得详细的显微组织信息。测得了上贝氏体、下贝氏体和粒状贝氏体组织中有明显不同的位向错配界面角度。基于这些测定结果,提出界定不同类型贝氏体的新定义和分类系统。基于鉴定统计图像分析结果提出复杂贝氏体显微组织的自动定量分析计算机模型。应用称作图像分类器的先进方法,开发了复杂贝氏体组织的鉴别和定量方法学。对单一和复杂的贝氏体显微组织试样做了拉伸、冲击和硬度的测量,并分析了对不同组织的影响,开发了贝氏体钢改进的结构-性能关系,它涉及一些和全部的控制因子,如:铁的本征强度,固溶强化,结构尺度因子(晶粒大小或板条尺寸),位错密度和第二相析出强化。归纳起来,主要成功在于改进贝氏体钢的结构-性能关系和建立复杂贝氏体组织的自动定量化计算机模型。这样人们能从控制好贝氏体显微组织性能的角度来确认贝氏体的形态。Bainitic microstructures in steels can offer dramatic combinations of strength and toughness and are now attracting our attentions. The bainitic microstructures derived their favorable balance of strength and toughness from the mixture of ultrafine bainitic ferrites with second phases distributed between inside bainitic ferrites. There are great financial benefits to be realized by optimization of chemical composition and processing parameters of industrial bainitic steels without the need for subsequent heat treatments. Sixteen kinds of bainitic steel divided into four groups with different type of bainite are selected and produced covering the range of carbon content from 0.06% to 1.00% by Zajac et al to control them to get single and complex bainitic microstructure. They provide single and complex bainitic microstructures. They put the CCT and TIT diagram are used for measurement of dilatometry, to determine the proper heat treatments process, to get the whole bainitic microstructure and to carry out the tensile and impact test for sample. More detailed microstructural information is obtained using high resolution scanning electron metallography （FEG-SEM） and back scattered electron diffraction （EDSP）. The clearly difference misorientations on the interface is measured in the upper, lower and granular bainite structure. Based on these results a new definition of bainite catalogue as well as a new classification system has been proposed. A computer module for automatic quantitative analysis of the complex bainitic microstructures based on supervised statistical image analysis has been developed. Using the advanced method, called Image Classifier, a methodology is already proposed and the identification and quantitative methodology of com- plex bainitic microstructures is dereloped. Measurement of tensile, impact and hardness have been carried out on samples with single and com- plex bainitic microstructures. The effect of their different bainitic microstructures upon mechanical properties has been a

关 键 词：贝氏体 贝氏体转变 固态相变 显微组织 

分 类 号：TG142.1[一般工业技术—材料科学与工程]