钢中马氏体和贝氏体基体组织的特征  

Matrix Structure of Martensite and Bainite in Steels

作　　者：古原 忠[1] 殷匠（译）[2] 

机构地区：[1]东北大学金属材料研究所,日本 [2]《热处理》编委

出　　处：《热处理》2009年第2期16-21,共6页Heat Treatment

摘　　要：板条马氏体和贝氏体组织中板条束和板条块尺寸的细化对于高强度结构钢的强化和韧化是重要的。在奥氏体晶界形核的贝氏体铁素体的晶体取向(变体)强烈地受制于其形核处即奥氏体晶界的性质,在小过冷度下产生粗大的板条束/板条块。当相变温度降低或碳含量减少时,更多的贝氏体铁素体变体在晶界形成,细化了板条束和板条块尺寸。这是由于形核能力较小的贝氏体铁素体变体更容易以较大的驱动力形成,而且由于塑性协调的抑制,伴随不同贝氏体铁素体变体形成而产生的相变应变的自协调也增加。尽管是类似的变体选择,但含碳量的增加将导致板条马氏体中板条束/板条块的尺寸减小。这是因为在Ms温度下驱动力随含碳量的变化较小,以及马氏体转变温度比贝氏体的低,能在更大范围内自协调。Refinement of packet and block sizes in lath martensite and bainite structures is important to strengthening and toughening of high-strength structural steels. The crystal orientation （variant） of bainitic ferrite （BF） is strongly restricted by natures of the austenite grain boundary where it nucleates, resulting in coarse packets/blocks for small undercooling. As transformation temperature is lowered or carbon content decreases, more BF variants form at a grain boundary and the block/packet sizes are refined. The reason is as follow：BF variants with less nucleation potency can form more easily with a larger driving force and self-accommodation of transformation strain by formation of different BF variants is also enhanced due to suppression of plastic accommodation. In spite of similar variant seleetion, an increase in carbon content leads to a decrease in packet/block sizes in lath martensite because there is a small change in driving force at the Ms temperature with carbon content and more extensive self-accommodation for martensite due to lower transformation temperatures than bainite.

关 键 词：马氏体 贝氏体 相变 控制轧制 位错 

分 类 号：TG142.11[一般工业技术—材料科学与工程]