Lv Z.Q.,Yanshan University |
Lv Z.Q.,Institute for Structural Materials |
Shi Z.P.,Yanshan University
Advanced Materials Research | Year: 2012
The crystal structure of alloyed austenite distorted after Ni and Co replaced Fe. The crystal type of austenite changed from cubic structure to tetragon or orthorhombic structure due to the influence of Co and Ni. The ratio (B/G) for γ-Fe (C) is equal to 2.841, which is higher than that for other alloyed austenite with Co and Ni. The workability of alloyed austenite with Co and Ni are poorer than γ-Fe (C). The formation of alloyed austenite needs more energy than γ-Fe (C) at ambient conditions. © (2012) Trans Tech Publications.
Chai F.,Institute for Structural Materials |
Yang C.-F.,Institute for Structural Materials |
Su H.,Institute for Structural Materials |
Chen X.-H.,Institute for Structural Materials
Journal of Iron and Steel Research | Year: 2012
Microstructures and mechanical properties difference of V and V-N microalloyed bulb-flat steel was ana-lyzed, and strengthening and toughening mechanism of experimental steel was further discussed. The results show temperature field of bulb-flat steel is nonuniform during cooling after finish rolling. The cooling rate in the center of the bulb is much higher than that in the flat. The temperature difference between center and flat is about 120°C when the finish rolling temperature is 950°C. Yield strength of bulb-flat steel is increased significantly and strength difference between center and flat is only 5 - 10 MPa by using V-N microalloyed technology designing. The microstructures of experimental steel is also refined, the average ferrite grain size difference between center and flat is only 1.24μm which improve the impact toughness of steel ultimately. The slower cooling rate promote the precipitation of V(C, N), and refining the second particles at the same time, which improve the section homo-geneity caused by different cooling rate and pass deformation.
Chen X.-P.,Institute for Structural Materials |
Wang X.-D.,Institute for Structural Materials |
Liu Q.-Y.,Institute for Structural Materials |
Mi F.-Y.,Institute for Structural Materials |
And 2 more authors.
Kang T'ieh/Iron and Steel (Peking) | Year: 2010
The mechanism of P-RE combined action improving atmospheric corrosion resistant performance of iron and steel material was studied. The Rust layers of experimental steels were made by using an accelerating industrial atmospheric corrosion test of dry-wet cyclic immersion. Furthermore XRD were used to measure and analyze rust layers. Under thin water film, the initial corrosion processes of experimental steels were observed and the changes of micro-area PH value of experimental steels were measured. The results are as follows: P-RE combined action promotes the formation of α-FeOOH. P-RE combined action changes properties of inclusion, affects the change of PH value, influences the process of corrosion and promotes the formation of protective rust layers.