In the past few years cool deformation research at McGill Univ.has been centered on experimental steels.In this work an X70 industrial grade is examined by means of torsion testing.Following a full hot rolling physica...In the past few years cool deformation research at McGill Univ.has been centered on experimental steels.In this work an X70 industrial grade is examined by means of torsion testing.Following a full hot rolling physical simulation,three levels of cool deformation strain,0.06,0.12,and 0.2 were applied at 400 o C and the subsequent strength were measured at room temperature;and the results were compared with the no-cool deformation situation.The effect of cooling rate after the finishing stage on the cool deformed microstructure and properties was also examined.The results show that by applying even a small amount of deformation,the yield point increases remarkably.展开更多
EBSD characterization of density and dispersion of high angle boundaries was carried out in niobium microalloyed steels of HTP base chemistry with 0.09 wt % Nb,which were thermo-mechanically processed under laboratory...EBSD characterization of density and dispersion of high angle boundaries was carried out in niobium microalloyed steels of HTP base chemistry with 0.09 wt % Nb,which were thermo-mechanically processed under laboratory conditions.Similar studies were carried out in higher grade (X-100 and above) line pipe steels with different chemistries,which were processed under simulation of industrial rolling conditions.The twin objectives are (i) to understand the effect of chemistry and processing parameters on the density and dispersion of high angle boundaries,and (ii) to correlate the microstructure and density of high angle boundaries with strength and fracture properties.The present studies confirm that refinement of austenite grain size prior to pancaking,large strain accumulation in austenite conditioning,alloy design with high hardenability and high cooling rates are essential to control high density and uniformity of dispersion of high angle boundaries in the final microstructure in order to achieve high strength,toughness,low DBTT and consistently 100% ductile shear in DWTT in thermo-mechanically rolled higher grade line pipe steels.展开更多
基金Financial supports of the Natural Sciences and Engineering Research Council of Canada(NSERC)Evraz Inc.NA
文摘In the past few years cool deformation research at McGill Univ.has been centered on experimental steels.In this work an X70 industrial grade is examined by means of torsion testing.Following a full hot rolling physical simulation,three levels of cool deformation strain,0.06,0.12,and 0.2 were applied at 400 o C and the subsequent strength were measured at room temperature;and the results were compared with the no-cool deformation situation.The effect of cooling rate after the finishing stage on the cool deformed microstructure and properties was also examined.The results show that by applying even a small amount of deformation,the yield point increases remarkably.
基金CBMM,BrazilChinese Government scholarship+1 种基金Evraz Inc NA,ReginaNSERC,Canada
文摘EBSD characterization of density and dispersion of high angle boundaries was carried out in niobium microalloyed steels of HTP base chemistry with 0.09 wt % Nb,which were thermo-mechanically processed under laboratory conditions.Similar studies were carried out in higher grade (X-100 and above) line pipe steels with different chemistries,which were processed under simulation of industrial rolling conditions.The twin objectives are (i) to understand the effect of chemistry and processing parameters on the density and dispersion of high angle boundaries,and (ii) to correlate the microstructure and density of high angle boundaries with strength and fracture properties.The present studies confirm that refinement of austenite grain size prior to pancaking,large strain accumulation in austenite conditioning,alloy design with high hardenability and high cooling rates are essential to control high density and uniformity of dispersion of high angle boundaries in the final microstructure in order to achieve high strength,toughness,low DBTT and consistently 100% ductile shear in DWTT in thermo-mechanically rolled higher grade line pipe steels.