J.B. Liu
,
L.J. Hu
,
Y.T. Wang
,
Z.Q. Liu
,
K. Miao
,
Z.L. Tian
金属学报(英文版)
The transformation behavior and microstructure development in the heat affected zone
(HAZ) of 800MPa grade ultra fine structured steel was investigated. It was found that
the HAZ has intermediate temperature transformation characteristics in a wide range
of cooling rates, with the bainite sheaves consisting of bainite ferrite plates without
carbide precipitation and retained austenite in the fast cooling regime. At relatively
high cooling rates, which corresponded to low heat inputs, the hardness of the simulated
HAZ was above that of the base metal. When the cooling rate was below 9±C/s, the
welding HAZ would have an obvious softening. The analysis of transformation rates
in continuous cooling processes was completed by numerical differential method. The
result indicated that the microstructure transformation rate of the HAZ in 800MPa
grade ultra fine structured steel changed sharply to slow speeds when the cooling time
t8=5 is longer than 7s.
关键词:
ultra fine structured steel
,
null
,
null
,
null
,
null
乔志霞
,
刘永长
,
严泽生
,
付继成
,
王惠斌
材料科学与工艺
通过对马氏体的显微组织进行分析，并结合线膨胀试验得到的相变动力学信息研究了30CrNi3MoV低合金超高强钢中的马氏体相变特征，结果表明：淬火冷却30CrNi3MoV钢的相变产物包括低碳板条状和高碳针状两种马氏体形态，两者的形成在动力学曲线中截然分开，板条马氏体形成于Ms以下的较高温（310℃～260℃），相变过程中发生了碳的重新分配，造成富碳奥氏体微区的形成；高碳针状马氏体形成于Ms以下的较低温（260℃～170℃），由富碳奥氏体微区转变而成，板条马氏体形成速率远高于针状马氏体。
关键词:
低合金超高强钢
,
马氏体
,
相变速率
,
M。
