Microstructure and Mechanical Property of Copper Bearing Eutectoid Steel
Microstructure and Mechanical Property of Copper Bearing Eutectoid Steel
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DOI：
10.2355/isijinternational.48.1467
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发表时间：
2008-10
影响因子：
1.8
通讯作者：
M. Murakami;Youhei Takanaga;Nobuo Nakada;T. Tsuchiyama;S. Takaki
中科院分区：
文献类型：
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作者：
M. Murakami;Youhei Takanaga;Nobuo Nakada;T. Tsuchiyama;S. Takaki
对含Cu共析钢（Fe-0. 8% C-Cu合金）进行了等温热处理。显微组织观察表明，珠光体转变显着延迟通过添加铜，但珠光体的形态，如片层间距和块大小，几乎没有影响的Cu添加。通过对铁素体相的化学分析发现，在珠光体转变过程中，Cu通过界面扩散在铁素体和铁素体之间发生再分布，并在铁素体内同时析出。此外，在2%Cu钢中，在与等温珠光体转变相同的温度下发现了时效硬化行为。这说明铜在珠光体转变时没有完全析出，珠光体组织中的铁素体处于过饱和状态。珠光体钢的屈服强度和抗拉强度不仅取决于片层间距，而且还取决于铜粒子在铁素体相中的分散度。例如，添加2%的Cu使屈服强度和拉伸强度增加约250 MPa，而不会使延展性降低太多。
Isothermal heat treatment was performed for austenitized Cu bearing eutectoid steels (Fe–0.8%C–Cu alloys). Microstructural observations revealed that the pearlite transformation is significantly retarded by the addition of Cu, but the morphology of pearlite, such as lamellar spacing and block size, are hardly influenced by the Cu addition. From the result of chemical analysis for cementite phase, it was found that the redistribution of Cu had occurred between ferrite and cementite through the interfacial diffusion during pearlite transformation and then the precipitation of Cu takes place simultaneously within ferrite phase. Furthermore, in the 2% Cu steel, age hardening behavior was found at the same temperature applied to the isothermal pearlite transformation. This means that the precipitation of Cu does not complete on pearlite transformation and the ferrite in pearlite structure is in the supersaturated state. Yield strength and tensile strength of the pearlite steels depend on not only lamellar spacing but also the dispersion of Cu particles within the ferrite phase. For example, 2% Cu addition increases yield strength and tensile strength by about 250 MPa without reducing ductility so much.