Pearlite

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

Quantitative measurement of cementite dissociation in drawn pearlitic steel

Abstract: Fractional dissociation of cementite was quantified as a function of strain by measuring the volume change of cementite in the pearlitic steel. The amount of carbon dissolved into the ferrite was estimated from the decrease of cementite volume, to correlate with the hardness in different strain level. The hardness showed linear relationship with the carbon dissolved into the ferrite matrix, which is believed to contribute in strengthening the drawn wire. Defects introduced from the deformation were believed to lower the energy barrier of cementite break-ups and to enhance the dissolution of carbon into ferrite.

Banding and the nature of large, irregular pearlite nodules in a hot-rolled low-alloy plate steel: A second report

Abstract: The microstructure of a hot-rolled low-carbon plate steel has been examined using a combination of light microscopy and scanning electron microscopy. It has been found that in the hot-rolled condition, the microstructure consists of alternate bands of ferrite and pearlite, together with relatively large, irregular pearlite nodules. These large nodules were found to be comprised of pearlite, intragranularly nucleated ferrite (both Widmanstatten and idiomorphic), together with carbide-deficient and/or carbide-free regions. It is argued that the carbide-deficient and carbide-free regions form as a result of the premature initiation of the pearlite reaction, i.e. pearlite forms prior to the body of the austenite grains attaining the eutectoid composition. In order to model the formation of the banded structure, specimens were reaustenitized at 1050 °C for 10 min and furnace cooled. This heat-treatment cycle produced an austenite grain size which was less than the chemical banding wavelength. A model for the decomposition of austenite, under these conditions, is presented.

Effects of RE–Al additions and austenitising time on structural variations of medium carbon Fe–B cast alloy

Abstract: The aim of the present study is to investigate the effects of rare earth and aluminium on the structural variations of medium carbon Fe–B cast alloy under the same austenitising temperature and different austenitising times. It is observed that the as cast microstructure of Fe–B cast alloy consists of the eutectic boride, pearlite, martensite and ferrite. Moreover, the as cast eutectic boride structures are greatly refined, and a blocky, less interconnected boride network is obtained when rare earth and Al are added. After different austenitising times, in each case, the phases in modified Fe–B cast alloy consist of the boride and martensite. The addition of RE in Fe–B cast alloy accelerates the diffusion process of B and Fe atoms during austenitising. Based on this favourable condition, the numbers of the fractured boride networks and isolated granular borides increase with increase in austenitising time. The boride volume fraction, Vickers hardness of martensite matrix and boride, and Rockwell h...

High-strength thick steel plate having excellent brittle crack propagation-stopping performance

Abstract: PROBLEM TO BE SOLVED: To provide a high-strength thick steel plate having excellent brittle crack propagation-stopping performance, and to provide a method for producing the same. SOLUTION: The high-strength thick steel plate contains as chemical components, by mass, 0.04 to 0.15% C, 0.1 to 0.5% Si, 0.5 to 2.5% Mn, ≤0.02% P, ≤0.01% S, 0.001 to 0.1% Al, 0.003 to 0.05% Nb, 0.005 to 0.02% Ti and 0.001 to 0.008% N, and the balance iron with inevitable impurities, and the microstructure is a ferrite or/and pearlite structure where bainite is used as a host phase. In the case the structure is divided into the three layers in a sheet thickness central part region around the sheet thickness central part of the steel sheet, and front-rear layer part regions other than that, a texture where the (111) or/and (211) X-ray face intensity ratio parallel to the rolling face is 1.5 to <2.0 is included in the central part region of 10 to <50% of the sheet thickness, and a texture where the (100) X-ray face intensity ratio parallel to the rolling face is ≥2.0 is included in the front-rear layer part regions other than that. COPYRIGHT: (C)2008,JPO&INPIT