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本文对ZG25铸钢以不同的加热温度和不同的冷却速度形成魏氏组织的规律进行了研究。结果表明,无论是细小的9号奥氏体品粒还是粗大的1号奥氏体晶粒,只要冷却速度适宜都可以产生魏氏组织。这说明魏氏组织是一种正常的组织转变产物。而不是过热的标志。也探讨了魏氏组织对钢的力学性能的影响,认为在相同奥氏体晶粒度下有魏氏组织的退火组织比无魏氏组织的具有较高的综合力学性能,主要表现在强度和冲击韧性的提高及韧脆转变温度下降。作者队为,韧性的提高是由于伴随魏氏组织的产生,有效地细化铁素体晶粒和珠光体晶团的结果;相反地,退火组织的晶粒粗大及沿铁素体晶界析出碳化物导致其脆性增加。同时初步探讨了等轴铁素体和针状铁素体的亚结构,结果表明,两者的位错组态无本质区别,只是位错密度不同而已。
In this paper, the regularity of forming Widmanstatten of ZG25 cast steel with different heating temperature and different cooling rate was studied. The results show that, whether it is a fine No. 9 austenite grain or coarse No. 1 austenite grain, as long as the appropriate cooling rate can produce Wei’s tissue. This shows that Wei’s organization is a normal product of organizational change. Not a sign of overheating. The effect of Widmanstatten on the mechanical properties of steels was also discussed. It is concluded that there is a higher comprehensive mechanical property of the Widmanstatten annealed microstructure than the non-Widmanstatten microstructure under the same austenite grain size, which is mainly reflected in the strength and Improved impact toughness and ductile-brittle transition temperature. The author’s team is that the improvement of ductility is the result of the refinement of ferrite grains and pearlite grains accompanied by the production of Widmansticks. On the contrary, the grain size of the annealed grains is coarse and precipitates along the ferrite grain boundaries Carbides lead to increased brittleness. At the same time, the sub-structures of equiaxed ferrite and acicular ferrite were preliminarily explored. The results show that there is no essential difference between the dislocation configurations of the two, only the dislocation density is different.