The colored metallography was used to inves- tigate the morphology of martensite in Fe-Ni-C al- loys.By compression deformation martensite trans- forms from lenticular to thin-plate.It is proved that the bended and br...The colored metallography was used to inves- tigate the morphology of martensite in Fe-Ni-C al- loys.By compression deformation martensite trans- forms from lenticular to thin-plate.It is proved that the bended and broken martensites are inher- ent from compressive predeformation of austenite.展开更多
The existence of residual austenite in weld metal plays an important role in determining the properties and dimensional accuracy of welded rotors. An effective corrosive agent and the metallographic etching process we...The existence of residual austenite in weld metal plays an important role in determining the properties and dimensional accuracy of welded rotors. An effective corrosive agent and the metallographic etching process were developed to clearly reveal the characteristics of residual austenite in the weld metal of a 9Cr1MoNbV welded rotor. Moreover, the details of the distribution, shape, length, length-to-width ratio, and the content of residual austenite were systematically characterized using the Image-Pro Plus image analysis software. The results revealed that the area fraction of residual austenite was approximately 6.3% in the observed weld seam; the average area, length, and length-to-width ratio of dispersed residual austenite were quantitatively evaluated to be （5.5 ± 0.1）μm2, （5.0 ± 0.1）μm, and （2.2 ± 0.1）, re-spectively. The newly developed corrosive agent and etching method offer an appropriate approach to characterize residual austenite in the weld metal of welded rotors in detail.展开更多
To study the growth of austenitic shells around the spheroidal graphite,color metallography has been employed.It is found that the shell is not a continuous layer of austenite,but a clus- ter of wedge-shaped crystals....To study the growth of austenitic shells around the spheroidal graphite,color metallography has been employed.It is found that the shell is not a continuous layer of austenite,but a clus- ter of wedge-shaped crystals.Three types of shells have been observed.That may strongly af- fect the deterioration of the spheroidal graphite.The mechanism of the formation of the austenitic shells has also been discussed.展开更多
文摘The colored metallography was used to inves- tigate the morphology of martensite in Fe-Ni-C al- loys.By compression deformation martensite trans- forms from lenticular to thin-plate.It is proved that the bended and broken martensites are inher- ent from compressive predeformation of austenite.
文摘The existence of residual austenite in weld metal plays an important role in determining the properties and dimensional accuracy of welded rotors. An effective corrosive agent and the metallographic etching process were developed to clearly reveal the characteristics of residual austenite in the weld metal of a 9Cr1MoNbV welded rotor. Moreover, the details of the distribution, shape, length, length-to-width ratio, and the content of residual austenite were systematically characterized using the Image-Pro Plus image analysis software. The results revealed that the area fraction of residual austenite was approximately 6.3% in the observed weld seam; the average area, length, and length-to-width ratio of dispersed residual austenite were quantitatively evaluated to be （5.5 ± 0.1）μm2, （5.0 ± 0.1）μm, and （2.2 ± 0.1）, re-spectively. The newly developed corrosive agent and etching method offer an appropriate approach to characterize residual austenite in the weld metal of welded rotors in detail.
文摘To study the growth of austenitic shells around the spheroidal graphite,color metallography has been employed.It is found that the shell is not a continuous layer of austenite,but a clus- ter of wedge-shaped crystals.Three types of shells have been observed.That may strongly af- fect the deterioration of the spheroidal graphite.The mechanism of the formation of the austenitic shells has also been discussed.
