Pearlite

About: Pearlite is a research topic. Over the lifetime, 6028 publications have been published within this topic receiving 65695 citations.

Quantitative assessment of strengthening parameters in ferrite-pearlite steels from microstructural measurements

Abstract: The influence of various ferrite–pearlite microstructures on the hardness and proof stress of a range of C–Mn steels has been studied with respect to a Hall–Petch analysis. In contrast with previous reports, the average pearlite interlamellar spacing was best found to quantify the microstructure when account is also taken of the ferrite volume fraction, austenite grain size, and calculated cementite lamella thickness. The mean uninterrupted distance in the ferrite described by a simple law of mixtures was found to correlate well with measured hardness. Although this parameter gave good agreement with strength figures an improved prediction was suggested by considering an equation of the form σ ys C = σo + [K α + (K α − K α )V p ]d c −1/2, where the composite ferrite grain size d c can be expressed as d c 1/2 = V p d p 1/2 + V α d α 1/2, σo is the friction stress, and V p and V α are the volume fractions of pearlite and ferrite, respectively. Similarly, K p and K α are the Hall–Petch parameters for...

A model for ferrite/pearlite band formation and prevention in steels

Abstract: A model for predicting the conditions under which ferrite/pearlite band formation occurs, and therefore the conditions in which it can be avoided in steels, has been developed. The model requires as input the alloy composition and microchemical segregation wavelength, and provides in turn the homogenization temperature and time in which the alloy should be held in the austenite region for band elimination. The model was applied to three alloys and predicted with accuracy the conditions under which bands were observed to disappear in different investigations from literature. The conditions under which the model can be applied to any alloy are explored.

Influence of Prior Warm Deformation on Cementite Spheroidization Process in a Low-Alloy Medium Carbon Steel

Abstract: Warm deformations have been applied to a low-alloy medium carbon steel (AISI 5140) to promote faster spheroidization during soft annealing treatments. The application of warm deformation leads to the fragmentation of cementite lamellae and the formation of defects on both cementite and the matrix. This induces faster lamellae break-up according to a boundary splitting mechanism, which is responsible for the improved spheroidization after annealing. The substructure developed in the matrix enhances pipe diffusion through the sub-boundaries, which helps the lamellae terminations to coarsen and causes lamellae fast splitting and finally yields a coarse cementite particle distribution. When deforming up to e = 0.3, almost fully spheroidized microstructures are obtained after annealing at 993 K (720 °C), independently of the initial pearlite features. By means of the EBSD technique, it has been observed that the applied warm deformation, in addition to enhancing the degree of spheroidization, allows a much finer microstructure to be formed after annealing. Grain refinement takes place as a consequence of a continuous recrystallization process, which is directly related to cementite spheroidization in the long term.