1． why does the metal with finer grains have not only higher strength and hardness but also higher plasticity and toughness than those of coarse grains at room temperature?
为什么精加工的多齿金属不仅在强度和硬度上,而且在塑性和韧性方面都比常温下的粗糙双齿金属要好
2． How should ones process the conductor made of copper wire after cold-drawing it?why?
如何加工处理冷却拉深以后的铜线材制造的导体?为什么
3． The melting points of Zn,AL,and Sn are known to be 419.c,660.c and 232.c
Respectively Calculate the minimum temperatures of recrystallization of them?
锌,铝和锡的熔点我们都知道是419摄氏度,660摄氏度和232摄氏度,分别计算他们达到结晶的最底温度
4.What is the difference between a phase and a microconstituent?
相位和微元素的不同点?
5.What is carbon content of an iron-carbon alloy for which the fraction of total ferrite is 0.94?
铁碳合金的碳含量是多少,对于全部铁酸盐中的每一小部分的含量是0.94?
6.Why are manganese sulphide inclusions in steel preferable to iron sulphide ones?
为什么钢中的锰流化物夹杂比铁中的流化物要好
7.“Quality of high-carbon steel is better than that of low-carbon steel”.is right this statement?
高碳钢的质量比低碳钢要好,正确吗?
What standard is quality (good or bad) of steel specified according to?Why?
关于钢的质量好坏的标准是依据什么?为什么
8.(a) What is the distinction betweem hypoeutoid and hypereutectoid steels?
A 和B两种钢的区别是什么?
(b) In a hypoeutectoid steel,both eutectoid and proeutectoid ferrit exsist.Explain the difference between them.What will be the carbon concentration in each?
在B种钢中,
9.Completely label Figure :完全分类
10.Draw two isomorphous phase diagrams ,one with a large freezing range between the liquidus and solidus,the other with a small freezing range between the liquidus and solidus.In which of the two alloy systems do you expect a greater amount of segregation?Explain
11.Analyze the crystallization procrss of alloy I in figure3-18
12.Refer to Figure 3-30.If the first precipitate to be formed when an alloy is cooled has 60 percent solid B,determine the overall liquid composition.
13.Once more refer to Figure3-30.At an overall composition of 50 percent B,it is found that the liquid phase contains 40 percent B and the solid phase contains 80 percent B.Determine the percentage of the solid and the liquid present.