Beneficial stress-strain behavior of moly-columbium steel line pipe

Effect of grain refinement to 1μm on strength and toughness of dual-phase steels

“…These features have been attributed to residual stresses and dislocation heterogeneities present in the ferrite as a result of the austenite-to-martensite transformation [27][28][29][30]. This transformation involves a volume expansion of 2-4%, depending on chemical composition [31], causing an elastically and plastically deformed zone in the ferrite adjacent to martensite [7,32,33]. The elastic stresses facilitate plastic flow during the early stages of yielding.…”

Introduction

“…The additions of manganese were increased, and also nickel and/or copper were added. 56 In the materials having lower yield ratios, rapid work-hardening can exceed any drop in yield strength due to the Bauschinger effect. This tendency led to a decrease in yield strength of tensile specimens taken after pipeforming due to the Bauschinger effect, 49 which meant a reduction of the plastic stability of rolled plates as materials for high-strength pipes.…”

“…The a grain refinement and the decrease in the pearlite fraction caused an increase in yield ratio (LYP: UTS) of rolled products. 56 The structure of the steels is typically acicular a or low-carbon bainite, retaining a distinct boundary for the prior y grains after normalizing or normal rolling, i.e. The small difference between the stress for the start of deformation and the fracture stress was not favourable if the materials were to be used for other structures.…”

Meetings Calendar

“…June [20][21][22]1983: Advanced Scanning Electron Microscopy Techniques; Lehigh University, Bethlehem, Pennsylvania. The course will discuss such topics as instrumentation, quantitative steriography and computer-aided imaging, characterization of electronic materials, EDS and WDS x-ray analysis, and x-ray qualification.…”

“…April [21][22]1983: Boundary Phenomena in Metallic, Ceramic and Metallic-Ceramic Interfltces; Bad Nauheim, West Germany.…”