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发表于 2009-2-27 12:39:34
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来自： 欧盟
按照GB/T 1348-1998的要求来看，Q400-18在室温（23+-5）的冲击功要求为14J，-20无要求。! M1 \$ f6 I# ], \
Q400L-18的-20冲击功要求为12J，单个最小9J! p ]4 M7 ]) |9 E
一篇论文的摘要：
2 Y7 p5 x/ Q& n# L* g铁路机车用曲轴箱体采用QT400-18L制造，出于安全考虑，对零件的低温性能提出了更高的要求。试验在QT400-18L中加入1.0%~1.8%的镍进行合金化并采用两阶段退火工艺进行热处理。分别测试试样在-20、-40、-60℃条件下的冲击韧度。结果表明，镍加入量从1.0%增加到1.8%，低温冲击韧度随镍加入量的增加而降低，微观组织由铁素体＋部分珠光体＋石墨球＋极少量碳化物组成。因此，Ni加入量必须<1.0%。
' o9 D% d+ o+ ?; c; W& O6 p }2 j) K3 mCrankcases of engine used in high-speed railway are made of QT400-18L. On account of safety, a higher property at low temperature is necessary. In this work, 1.0%~1.8% Ni added into the ductile iron it for alloying and heat treated as two-step annealing. The impact toughness of the specimens was measured at three kinds of low temperatures. The results show the impact toughness of the samples reduces as the content of Ni increasing from 1.0% to 1.8%, and the microstructure of ductile iron are composed of ferrite, nodular graphite, pearlite and a traces of carbonization. It illustrates that the amount of Ni has to be less than 1.0%. |
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发表于 2009-2-27 12:35:48
楼主
谢谢
