Effects of a High Magnetic Field on Microstructure and Texture Evolution in a Cold‐rolled Interstitial‐Free (IF) Steel Sheet during Annealing

Abstract

In the past few decades, the effects of magnetic field on metallurgical phenomena have received great interest in relation with the modification of microstructure and the development of high-performance magnetic materials. [1±3] However, only limited studies have focused on recrystallization and recrystallization texture development in magnetic materials during magnetic field annealing. It was found that the application of a magnetic field could (i) produce some changes in the recrystallization texture in the case of a cold-rolled Fe-Co alloy, [4,5] (ii) introduce the <111> and <112> texture components with a swaged iron wire, [6] (iii) retard recrystallization and increase the {100} recrystallization texture component in the case of a cold-rolled Armco iron, [7] (iv) increase the frequency of low-angle boundaries in an Fe-Co alloy [8] and Fe3%Si alloy [9] and enhance the selectivity of the <001> axis alignment in an Fe-3%Si alloy. [9] With the current development of the cryocooling technique, high magnetic fields of over 10 T have become available at a reasonable in-lab cost. In this paper, we present a comparative study on the impact of a high magnetic field on the microstructure and texture evolution in a cold-rolled IF steel sheet during annealing.The material used in this study was a 76 % cold-rolled IF steel sheet of 1 mm thickness, with a chemical composition of (wt.%): 0.0023 C, 0.056 Ti, 0.014 Si, 0.16 Mn, 0.011 P, 0.0064 S, 0.052 Al, 0.0018 N. Specimens were taken from the sheet in a longitudinal direction parallel to the rolling direction. The isothermal annealing treatments were carried out in a furnace installed in a cryocooler-cooled superconducting magnet capable of generating a high magnetic field of 11 T. [10] For comparison, the specimens were heated to the peak temperatures selected, ranging from 650 to 850 C at a heating rate of 50 C/min in an argon-flow atmosphere and cooled in the furnace after 25 min of holding time, respectively with and without applying a 10 T magnetic field. In both cases, the specimens were placed in the center of the magnetic bore with their rolling direction (RD) parallel to the magnetic field direction (MD). The experimental setup is schematically shown in Fig. 1.The X-ray texture measurements were performed for the cold and annealed specimens at their one-quarter thickness by measuring three incomplete {110}, {200} and {211} pole figures up to a maximal polar angle of 70 with the Schulz back-reflection method. [11] The corresponding ODFs were calculated with the two-step method [12] and the results were presented in constant j-sections (Roe's notation). The microstructure of the longitudinal section of the specimens was examined with an optical microscope. For the specimens annealed at 700 C, the local orientations on the RD-ND plane close to the specimen center were measured using a SEM-EBSD system. The scan was carried out over a grid size of 192 x 120 with 2 lm spacing. The average indexed fractions of the two specimens was above 90 %. The microhardness tests ...

Theoretical Analysis on Crystal Alignment of Feeble Magnetic Materials under High Magnetic Field

“…In fact, the high magnetic field can fabricate textured microstructures even for feeble magnetic materials, when the anisotropic magnetic energy on the magnetization is strong enough to align crystal particles. [8][9][10][11][12][13][14][15] Many materials have the magnetic anisotropy of crystals, namely magnetic susceptibility is different in each crystal axis and thus the crystals can be rotated to align to a preferred direction. Recently, the application of high magnetic field for control of structures of materials is recognized as one of the useful technologies in materials processing.…”

A Novel Process to Fabricate of Highly Textured Ceramics in a High Magnetic Field

“…This principle can be applied not only to magnetic materials but also to non-magnetic materials with asymmetric unit cells. [1][2][3][4][5][6][7][8][9][10][11] When materials are placed in a magnetic field, crystals exhibiting anisotropic magnetic susceptibility orient themselves with the direction of the maximum susceptibility parallel to the magnetic field. Silicon nitride ceramics have been identified as one of the promising structural ceramics with high strength at high temperature, good thermal resistance due to the low thermal expansion coefficient, and good resistance to oxidation.…”

Effect of High Magnetic Field Annealing on Microstructure and Texture at the Initial Stage of Recrystallization in a Cold-Rolled Interstitial-Free Steel

“…As an important external field, it has been evidenced experimentally that magnetic field can affect the development of recrystallization and recrystallization texture in plastically deformed metallic materials, [1][2][3][4][5][6][7][8][9] especially in ferromagnetic materials. [1][2][3][4][5][6][7] While for ferromagnetic materials, the study of magnetic field annealing on recrystallization and texture evolution in silicon steel sheet and IF deepdrawing steel sheet has been an object of great attention.…”

“…[1][2][3][4][5][6][7] While for ferromagnetic materials, the study of magnetic field annealing on recrystallization and texture evolution in silicon steel sheet and IF deepdrawing steel sheet has been an object of great attention. As reported else where, 6,7) the research work of high magnetic field annealing on recrystallization and texture evolution in IF steel sheet was mainly focused on the grain growth stage, by changing the annealing temperatures at a range of 650$850 C, and the holding time at an annealing temperature (750 C) near Curie point. The results show that the recrystallization and the subsequent grain growth were retarded by the magnetic field annealing, and the recrystallization texture development was retarded to some extent, too.…”