The relation between microstructure and yield strength in tempered low-carbon lath martensite with 5% nickel
The relation between microstructure and yield strength in tempered low-carbon lath martensite with 5% nickel
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DOI：
10.1179/030634576790431868
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发表时间：
1976-12
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影响因子：
--
通讯作者：
L.-Å. Norström
中科院分区：
文献类型：
--
作者：
L.-Å. Norström
本文分析了含5%镍的低碳(-lt；0.10%)板条马氏体淬火回火后的拉伸屈服强度与晶粒度和亚结构参数的关系，同时研究了添加0.3%钼的影响。用透射电子显微镜对其微观结构进行了详细的研究。初始马氏体包控制着正常回火后的高角度晶界组织，从而通过对包尺寸的普通Petch-Hall关系来贡献屈服强度。如果出现广泛的回复和亚晶形成，则在回火时，小包的Petch-Hall系数似乎会减小。亚晶界和亚晶内的位错对屈服强度有很大贡献，并解释了这种类型的马氏体钢的高强度。回火软化主要是回复的结果，回复破坏了原有的板条组织，降低了最初较高的位错密度。添加0.3%的钼会严重阻碍回火回复，从而导致回火软化。Mo的这种显著影响可能是由于某些固溶体相互作用造成的，可能导致位错攀移的延迟。
The tensile yield strength of quenched and tempered low-carbon (< 0.10%) lath martensite with 5% nickel is analysed with respect to grain size and substructural parameters and at the same time effects from an addition of 0.3% molybdenum are investigated. Microstructures are studied in detail by transmission electron microscopy. The initial martensite packets control the high-angle boundary grain structure after normal tempering, thus contributing to the yield strength through an ordinary Petch-Hall relation for the packet size. The Petch-Hall coefficient for packets seems to decrease on tempering if extensive recovery and subgrain formation occur. Subgrain boundaries and dislocations within subgrains contribute substantially to the yield strength and account for the high strength of this type of martensitic steel. Softening on tempering is mainly a result of recovery through which the original lath structure is destroyed and the initially high dislocation density is reduced. The addition of 0.3%Mo strongly retards recovery and hence softening on tempering. This pronounced influence of Mo appears to be caused by some solid solution interaction probably resulting in retardation of dislocation climb.