ASSESSMENT OF THE EFFECT OF CARBON ON PERFORMANCE PROPERTIES AND THE MICROSTRUCTURE OF ROLL STEEL

This paper concentrates on studying the effect of carbon on performance properties of 150KhNM roll steel grade. The introduction contains a brief literature review on the effect of the roll alloy chemistry on performance and mechanical properties of mill rolls. Besides, it demonstrates the relevance of the presented studies. The paper describes the effect of chemical elements, such as manganese, niobium, vanadium, nickel on the microstructure and mechanical properties of mill rolls. It also classifies alloying elements by their effect on polymorphic transformation temperatures and shows carbide-forming elements increasing such property. We also considered the effect of the carbide phase on hypereutectoid steel. The paper contains carbide compounds that may be formed in steels, and their classification. It describes the mechanism of the effect of the carbide phase on performance properties of steel castings. The second part of the paper presents a research procedure and briefly describes materials used for the research and laboratory and analytical equipment. The third part of the paper presents the research results. It describes the effect of carbon in a broad range on service durability of hypereutectoid roll steel in conditions of wear at room and elevated (400 ºС) temperatures. Besides, we determined the effect of carbon on the roll alloy microstructure and analyzed relations between the microstructure and performance properties of hypereutectoid roll steel. The conclusion of the paper summarizes the results and contains the references used for an analytical review.

A multiscale mean field model for elastic properties of hypereutectoid pearlitic steels with different microstructures

Multiscale modeling of macroscopic elastic properties of pearlitic hypereutectoid steel using the Eshelby matrix–inclusion approach is possible. The model works through successive homogenization steps, based on the elastic properties of cementite and ferrite. Globular pearlite is homogenized using α Mori–Tanaka approach. Lamellar pearlite and pearlite colonies with fragmented proeutectoid cementite are homogenized by α classical self-consistent scheme. In the case of pearlite colonies surrounded by α continuous cementite film, α generalized self-consistent scheme is used. The influence of microstructural parameters such as the pearlite colony size or the thickness of the proeutectoid cementite on Young’s and shear moduli and on coefficients of the stiffness tensor is simulated. Proof of concept is obtained by comparison between predicted elastic behavior and experimental results from the literature.