XIE Changsheng SUN Peizhen ZHAO Jiansheng SUN Desheng Huazhong University of Science and Technology
,
Wuhan
,
China
金属学报(英文版)
The inheritance phenomenon of precipitated V_4C_3 in martensitic transformation has been in- vestigated by means of electron diffraction and matrix analysis.A crystallographic orientation relation among austenite,martensite and V_4C_3 carbide was found to be. (010)_A∥( 10)_M∥(010)_(v_4c_3), [10 ]∥[11 ]_M [10 ]_(v_4c_3) The V_4C_3 first precipitated in austenite,and then was inherited to martensite.Although cer- tain orientation relation was kept between V_4C_3 and martensite,the interfacial structural ana- lysis pointed out that the biphase interfacial energy is higher than that determined by Baker-Nutting relation,thus it is metastable.Because the V_4C_3 precipitated along the crystalline defects in austenite,they could be inherited to martensite.
关键词:
V_4C_3
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QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
China
金属学报(英文版)
The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.
关键词:
stress corrosion cracking
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