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粒状珠光体 ------曾经很纠结，现在已经释怀了 众所周知，含碳量0.77%的铁-碳合金的退火组织是层片状珠光体，过共析钢就是珠光体 + 二次渗碳体。 不过，共析钢、过共析钢球化退火后的组织，都被称之为“粒状珠光体”。实话说，一直不是很适应这样的称呼，因为，退火态的时候，组织组成物有差别，一个是全部的珠光体，一个，还需要有二次渗碳体。而现在，都成了“粒状珠光体”，似乎“没差别了”。 这次在去成都的火车上，突然梳理清楚了。 高碳钢球化退火后的组织，都被称之为“粒状珠光体”，这是没有问题的。比照“亚共析钢退火组织”的描述可以这样说： 碳钢球化退火后的显微组织，基本类似，被称之为“粒状珠光体”，不过，随着含碳量的提高，组织中的颗粒状碳化物的数量会不断增多。 进一步说，颗粒状的尺寸大小，也是一个重要的参数，有所谓：粗颗粒、细颗粒、极细颗粒的分类。 我们提及“片状珠光体”的时候，铁素体、渗碳体都是“片状”，交替分布；粒状珠光体可就不是了，颗粒状只是在指渗碳体一个，而铁素体是呈现“等轴晶粒”的基体，或者说，是一个个“大颗粒”。 国内专业期刊可见对应的英文词汇有两个，spheroidal pearlite、granular pearlite。这和球化退火、球化组织的翻译倒是有些对应。 国外，似乎没有一个“粒状珠光体”的说法，只有“球化组织”一说。 参考资料： [1]
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[3] 球化退火国际上又叫做Spheroidizing annealing，主要意思是使钢中碳化物球化而进行的退火，得到在铁素体基体上均匀分布的球状或颗粒状碳化物的组织。 [4] 由铁素体和粒状碳化物组成。它由过共析钢经球化退火或马氏体在650℃~A1温度范围内回火形成。其特征是碳化物成颗粒状分布在铁素体上。 [5] 有这样的一些词汇：globular carbides、Spheroidized microstructure、spheroidizing treatment、spheroidizing reaction Spheroidizing. A very soft spheroidized structure can be obtained by full annealing. Such a structure is not as well suited for machining as the normalized and tempered structure. However, for severe cold-forming operations such as spinning, deep drawing, and wiredrawing, the soft and ductile spheroidized structure is preferred. Spheroidizing treatments are described in the text of this article. Spheroidizing: Heat to 760 to 775 °C （1400 to 1425 °F）and hold 4 to 12 h; cool slowly full spheroidizing anneal. spheroidite · An aggregate of iron or alloy carbides of essentially spherical shape dispersed throughout a matrix of ferrite. · spheroidizing · Heating and cooling to produce a spheroidal or globular form of carbide in steel. Spheroidizing methods frequently used are: 1. Prolonged holding at a temperature just below Ae1 2. Heating and cooling alternately between temperatures that are just above and just below Ae1 3. Heating to a temperature above Ae1 or Ae3 and then cooling very slowly in the furnace or holding at a temperature just below Ae1 4. Cooling at a suitable rate from the minimum temperature at which all carbide is dissolved, to prevent the reformation of a carbide network, and then reheating in accordance with method 1 or 2 above. （Applicable to hypereutectoid steel containing a carbide network.） [6] spheroidal graphite. Graphite of spheroidal shape with a polycrystalline radial structure. This structure can be obtained, for example, by adding cerium or magnesium to the melt. spheroidite. An aggregate of iron or alloy carbides of essentially spherical shape dispersed throughout a matrix of ferrite. spheroidized structure. A microstructure consisting of a matrix containing spheroidal particles of another constituent. spheroidizing. Heating and cooling to produce a spheroidal or globular form of carbide in steel. 一些可见的词汇：globular particles of cementite、globular secondary carbides、globular carbide particles、spheroidal cementite |
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