AN INVESTIGATION OF AGING BEHAVIOUR IN MICROALLOYED STEEL (X70) UOE PIPE
Aging of microalloyed steel pipe can occur at relatively low temperatures associated with the pipe coating process and/or during long term storage or use.The aging phenomenon is primarily attributed to C diffusion to dislocations and subsequent pinning of these dislocations.Important factors in the aging process include time,temperature,chemical composition and plastic deformation(arising from the pipe forming process).The work presented in this paper uses a Box-Behnken experimental design to determine the effect of time,temperature,location in the UOE pipe(90° or 180° to the weld),position through the pipe wall thickness(ID,CL or OD)and the steel”s C/Nb ratio(0.60,1.25 and 1.80)on the change in yield strength of three(uncoated)X70 UOE pipes.Quantitative microstructure analysis is undertaken to determine the grain size and microconstituent fractions of the as-received pipe material.Quadratic equations and response surface(s)correlating the significant aging variables with changes in the longitudinal yield stress of the pipe are developed.Both through thickness position and the C/Nb ratio,followed by aging temperature,had the largest effect on the change in longitudinal yield strength.
UOE pipe strain aging Box-Behnken microalloyed steel
J.B.Wiskel J.Ma D.G.Ivey H.Henein
Department of Chemical and Materials Engineering,University of Alberta,Edmonton,Alberta,Canada T6G 2V4
国内会议
杭州
英文
707-714
2015-11-11（万方平台首次上网日期，不代表论文的发表时间）