Conditions for Grain Boundary Bulging during Tempering of Lath Martensite in Ultra-low Carbon Steel

Study of tempering behavior of lath martensite using in situ neutron diffraction

“…Because α is dependent on the substructure, we should consider the effects on Δσ of not only ρ but also M* for deeper understanding [26]. Although Takebayashi et al [11] reported the rearranged dislocation structure in tempered martensite and Tsuchiyama et al [6] concluded that the dislocation distribution exhibited a uniform-to-nonuniform transition during tempering, they presented no quantitative evaluation of how the distribution of the dislocation varies with tempering temperature. Hence, the change in M* in Fig.…”

“…Tempering of asquenched martensite is important for controlling the strength and toughness of steels used for structural components. Various microstructural changes, including carbide precipitation [1][2][3], temper softening [4], retained austenite decomposition [1], disappearance of lath boundaries to become larger grains [5,6], recovery of the ferrite matrix [1], and annihilation of dislocations [6,7], have been characterized during the tempering of Fe-C martensite. Lindsley and Marder [2] suggested that the coarsening process in Fe-C binary alloys during tempering was controlled by carbon diffusion along grain boundaries and dislocations.…”

Microstructure and Micro Strain in the CGHAZ of 2.25Cr-1.6W Steel after Intercritical Heat Treatment

“…[9][10][11][12][13][14][15][16][17] Few reports study the crystallography of the transformation products. 8,13) The discussion of the transformation products is seldom analyzed from a different angle.…”

Effect of Tempering on Microstructure and Mechanical Properties of Laser Welded and Post-Weld Treated AHSS Specimens

“…The results of tempering at 636°C shows that tensile strength increased up to 11.1% and yield strength up to 10.6%, elongation shows also a rise of 32.9%. Replacement of a coarse cementite dispersion by finer alloy carbides and/or nitrides, more resistant to coarsening and recrystallization of martensite lath boundaries to an equiaxed ferrite grain structure at around 600°C can produce an increase in both strength and elongation [16,17]. A comparison between all specimens at different tempering temperatures is shown in Fig.…”