ROLE OF MICROSTRUCTURE ON STRENGTH AND TOUGHNESS OF FULLY PEARLITIC STEELS
ROLE OF MICROSTRUCTURE ON STRENGTH AND TOUGHNESS OF FULLY PEARLITIC STEELS
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DOI：
10.1007/bf02656606
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发表时间：
1976-01-01
期刊：
影响因子：
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通讯作者：
BERNSTEIN, IM
中科院分区：
文献类型：
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作者：
HYZAK, JM;BERNSTEIN, IM
为了阐明中等强度的全珠光体钢的组织-性能关系，并确定控制变形和断裂过程的关键显微组织特征，开展了一项实验程序。具体来说，屈服强度主要受层间珠光体间距的控制，而层间珠光体间距本身是等温转变温度的函数，在一定程度上是奥氏体晶粒尺寸的函数。对标准试样和疲劳预裂试样进行的Charpy试验表明，冲击能和动态断裂韧性的变化主要取决于奥氏体晶粒尺寸，随晶粒尺寸的减小而增加，随珠光体集落尺寸的减小而增加的程度较小。数据的统计分析证实了这些趋势，该分析确定了每个因变量对感兴趣的自变量值的相对贡献。结果表明，滑移位错与铁素体-渗碳体界面的相互作用控制了合金的变形行为，铁素体取向恒定的结构亚基控制了合金的断裂行为。初步数据表明，这些单位的尺寸受奥氏体晶粒尺寸的控制，但与奥氏体晶粒尺寸不完全相同。考虑了该骨折单元的可能起源。
An experimental program was carried out to clarify the structure-property relationships in fully-pearlitic steels of moderately high strength levels, and to identify the critical microstructural features that control the deformation and fracture processes. Specifically, the yield strength was shown to be controlled primarily by the interlamellar pearlite spacing, which itself was a function of the isothermal transformation temperature and to a limited degree the prior-austenite grain size. Charpy tests on standard and fatigue precracked samples revealed that variations in the impact energy and dynamic fracture toughness were dependent primarily on the prior-austenite grain size, increasing with decreasing grain size, and to a lesser extent with decreasing pearlite colony size. These trends were substantiated by a statistical analysis of the data, that identified the relative contribution of each of the dependent variables on the value of the independent variable of interest. The results were examined in terms of the deformation behavior being controlled by the interaction of slip dislocations with the ferrite- cementite interface, and the fracture behavior being controlled by a structural subunit of constant ferrite orientation. Preliminary data suggests that the size of such units are controlled by, but are not identical to, the prior-austenite grain size. Possible origins of this fracture unit are considered.