ZHENG Xiao-fei
,
KANG Yong-lin
,
MENG De-liang
,
AN Shou-yong
,
XIA Dian-xiu
钢铁研究学报(英文版)
The effect of cooling (laminar cooling) start temperature on the phase constitution was analyzed by quantitative metallography. The martensite/austenite (M/A) island distribution was fixed by colour metallography. The strength and uniform elongation of the steels were tested with quasi-static tensile testing machine. The in-coordinate deformation of the soft and hard phases was analyzed using FEM. The results indicate that when the cooling start temperature is 690 ℃, the mechanical properties are the best, meeting the requirements of X80 high deformability pipeline steel.
关键词:
high deformability pipeline steel
,
cooling start temperature
,
carbon diffusion
,
in-coordinate deformation
,
M/A island
NIU Tao
,
KANG Yong-lin
,
GU Hong-wei
,
et al
钢铁研究学报(英文版)
Using TEM, electron diffraction, EDX analysis and physicochemical phase analysis, the morphology, crystal structure, size distribution and chemical composition of precipitates in the microstructure of high strength Nb-microalloyed X100 pipeline steel were investigated, and the strengthening effect of precipitation was quantitatively calculated with Ashby-Orowan correction model. The precipitates obtained in X100 pipeline steel can be divided into two kinds: “complex” and “single” particles by morphology. The EDX analysis of single precipitates reveals that the chemical composition matches well with particle dimensions, especially the Nb/Ti ratio regularly reduces with the increase of particle size. The yield strength increments in the way of precipitation strengthening of X100 pipeline steel reached about 52MPa, which suggests that the precipitation strengthening is not the dominative strengthening mechanism for X100 pipeline steel.
关键词:
X100 pipeline steel;carbonitride;precipitation behavior;strengthening effect
