专业材成英语4.doc

专业材成英语4.doc2. 2. 4 Iron-Carbon Equilibrium Diagram
铁碳合金平衡相图
The struetural form of pure iron at room temperature is called ferrite a - 。Ferrite is soft and 软而可塑 Since ferr ite has a body-ce nt red cubic st rue tu re, the int er~a to mic spa ces are small and pronouncedly oblate, and cannot readily accommodate even a sm all carbon ，原子间距很小而无法容纳很小的碳原子 Therefore, solubility of carbon in ferrite is very low, of the order of % at room temperature. The maximum carbon content in ferrite is 0. 05% at 723°C ad dition to carbon,所以室温下碳在铁中的溶解度很低，最高才达到0. 006% 723°C时a cer tain amoimt of silicon, manganese and phosphorous may be found in %,除了碳外，铁素体也含有一定量的硅、猛和磷
The face-ce nt red modification of iron is called aus tenite or 丫- 构的铁称作奥氏体或Y铁。It is the stable form of pure iron at temperatures bet ween 910°C and 1400°°C至1400°C温度间的稳定形式
At its stable temperature austenite is soft and duetile and consequently, i s well suited for manufacturing processes・
在稳定温度下奥氏体柔软，可塑，因此很适用于制造过程
The face-centred cubic strueture of iron has larger inter-atomic spacing th an in so, in FCC s truetirre the interstices are barely large enough to accommodate carbon a/toms, a nd lattice strains are ，面心立方结构的间隙也难以大到足够容纳碳 原子 As a resuIt, not all the interstitial sites can be filled a