S.Q. Wang
,
Q.C. Jiang
,
X.H. Cui and Z.M. He(School of Materials Science and Engineering
,
Jilin University of Technology
,
Changchun 130025
,
China) Manuscript received in revised form 15 September 1998
金属学报(英文版)
By the modification, network carbide was disconnected at 1100℃ through uneven dissolution at higher energy places in carbide, where there is twin or lattice distortion,and granulated at 1130℃ through element diffusion. The stability of M7C3 carbide was decreased owing to the modification reducing the segregations of Cr and M0, thus the temperature, at which uneven dissolution of carbide commenced, was decreased. Also lattice distortion or defect such as twin in carbide was increased by the modification, which prompted widespread disconnections in carbide. In addition, the modification prompted element diffusion to accelerate the kinetics process of carbide granulation.
关键词:
ledeburite steel
,
null
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null
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X.H. Cui
,
Q.C. Jiang
,
S.Q. Wang and Z.M. He (School of Materials Science and Engineering
,
Jinn University of Technology
,
Changchun 130025
,
China)
金属学报(英文版)
Compared with conventional cast Cr12Mo V steel and forged Cr12Mo V steels, carbide morphology and properties of modified cast Cr12MoV steels were investigated by performing hardness test, impact test, fracture toughness test, fatigue crack propagation test, metallographic examination and quantitively metallographic analysis. The results indicate that the carbide morphology in modified cast steel is characterized by granular carbide uniformed- distributed, which is different from that of conventional cast steel, but similar to that of forged steel. The impact toughness of modified cast steel is distinctly increased to 12.75J/cm2 from 6.8J/cm2 in the conventional cast steel with networked carbide, because of carbide granulation. Furthermore, The fracture toughness and fatigue - cock-propagation threshoid of modified cast steel are not only higher than that of the conventional cast steel, but also higher than that of the forged steels.
关键词:
carbide
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null
,
null
,
null
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