Pearlite

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

Prediction of mechanical properties of multi-phase steels based on stress-strain curves

Abstract: An approach to predict mechanical properties of hot-rolled multi-phase steels referring to the stress-strain curves is proposed. Different from a conventional approach of regression analysis about the relationships between properties and chemical compositions and processing factors, a proposed one is based on the analysis and application of stress-strain curve: several commonly used mechanical properties such as yield strength, tensile strength, uniform elongation, total elongation, work-hardening exponent (n) and Vickers hardness, are derived systematically from the stress-strain curve of a multi-phase steel, which is calculated by using concentration factor, i.e., strain partition ratio and stress-strain curves of constituent phases. Stress-strain curves of individual component structures such as ferrite, pearlite, bainite, and martensite are expressed by Swift's equation. Physical background of the concentration factor is discussed by examining theoretical models of deformation for two-phase materials. Evaluation of plastic relaxation related to microstructural topology might be the most difficult point of this approach and some trials are presented.

Nondestructive characterization of microstructures and determination of elastic properties in plain carbon steel using ultrasonic measurements

Abstract: This paper presents a reliable and fast nondestructive characterization of microstructural and elastic properties of plain carbon steel, based on ultrasonic measurements for ultrasonic velocity and attenuation. Microstructures considered are: ferrite, pearlite, ferrite–pearlite and martensite. Ultrasonic velocities considered longitudinal and transverse waves and modulus of elasticity and modulus of shear were determined by correlations between them. In carbon steels, a lower value of ultrasonic velocity was observed for the martensite in relation to the other microstructures, while the opposite was observed in terms of ultrasonic attenuation. The results show that the use of ultrasonic measurements to obtain ultrasonic velocities and attenuations, in order to correlate them with the involved microstructures, as well as to determine the modulus of elasticity and modulus of shear, is very fast and reliable, permitting the characterization of nondestructive microstructural and elastic properties.

Effects of Microstructure on Corrosion of X70 Pipe Steel in an Alkaline Soil

Abstract: Corrosion of X70 steel with different heat treatments (quenching, air cooling, and furnace cooling) in an alkaline soil was investigated by weight-loss, surface characterization and electrochemical measurements. The cathodic/anodic reactions of X70 steel in alkaline soil are dominated by the oxygen reduction and formation of iron oxides that deposit on the steel surface. The protection of the oxide deposit is through a physical block effect. The deposit layer formed on as-received steel has a compact, complete structure and thus, provides an effective protection over the underneath steel. However, the deposit layers on the heat-treated steels are generally loose, porous and defective, and provide minor protectiveness. Corrosion of steel is affected by its microstructure. Generally, steels with heat treatments have a higher corrosion rate than the as-received steel. The presence of more pearlite enhances the corrosion rate of ferrite by a galvanic effect. When the steel contains bainite and martenite phases, the activity of the steel is further increased.