Materials Processing Fundamentals: Poster Session
Sponsored by: TMS Extraction and Processing Division, TMS: Process Technology and Modeling Committee
Program Organizers: Jonghyun Lee, Iowa State University; Guillaume Lambotte, Boston Metal; Samuel Wagstaff, Oculatus Consulting; Antoine Allanore, Massachusetts Institute of Technology; Fiseha Tesfaye, Metso Metals Oy, Åbo Akademi University

Tuesday 5:30 PM
February 25, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr

Session Chair: Jonghyun Lee, Iowa State University


M-66: Effects of Welding Conditions and Post Weld Heat Treatment on Precipitation of Widmanstätten-austenite of Duplex Stainless Steels: Yunxing Xia1; Xiaofu Zhang1; Fumikau Miyasaka1; Hiroaki Mori1; 1Osaka University
    The results of the laser welding of duplex stainless steels, super duplex and Lean duplex showed that the structure of the weld zone was significantly different between the steel grades, it was found that the increase in welding speed significantly reduced the formation of the austenite phase. To counterbalance the rate of ferrite phase /austenite phase by using the laser surface treatment after welding, it has become possible to recover a part of the content of the austenite phase even in the laser welded portion. Further, the microstructure of the austenite phase in laser welding portion which was precipitated due to the rapid cooling effect was observed by after using an etching solution.

Cancelled
M-67: Evaluation of Mechanical Properties of Welded Zn-Coated Steel Using Tandem MAG Welding Process: Jaesoo Lee1; Jong-Deok Seo1; Dong-Yoon Kim2; Munjin Kang2; 1Shin Young Co., Ltd.; 2Korea Institute of Industrial Technology
    When the zero-gap lap fillet joint of the Zn coated steel sheet is subjected to arc welding, the vaporized zinc may not escape from the molten pool during welding, and if left in the weld, causes a porosity defect. Porous defects remained in the welds deteriorate mechanical properties, and many studies have been conducted on how to reduce these defects. In this study, it has applied a tandem pulse MAG process to reduce the porosity at zero gap welding of 590MPa grade GA steel sheet. Tensile and fatigue tests were performed to investigate mechanical properties. And the pit and pore of welds were investigated through radiographic inspection. When the tandem MAG welding was applied, the pit and pore of the weld decreased compared to the single MAG welding. The tensile and fatigue strengths of tandem MAG welds increased 1.5 and 1.8 times, respectively, compared to single MAG welding.

M-68: Experimental and Numerical Investigation on Surface Damage of Cold Rolled Sheet Caused by Inclusion Movement: Xin Li1; 1University of Science and Technology Bejing
    In present work, samples were cut from ultra-low carbon steel slab to investigate the formation of surface damage induced by inclusions during cold rolling. Surface damage such as dent, peeling and pockmark were reproduced by rolling experiment. The inclusions such as Al2O3, SiO2, and MgO·xCaO were found in surface damages. FE method was employed to reveal the relationship between surface damage and Al2O3 inclusion movement. The initial position and size of inclusions are significant to the formation process of surface damage. 50μm Al2O3 inclusion located at the 1/8 of sheet thickness is easily rolled to the surface and causes the surface damage. Morphology of Al2O3 inclusion is difficult to change due to the higher hardness and larger elastic modulus. However, the Al2O3 inclusion can be crushed into pieces, which increase the damage of steel matrices. Surface damage was formed through the coalescence behavior of microscopic damages.

Cancelled
M-69: Heterogeneous Grain Microstructure Reducing/Eliminating Edge Breaks in Low Carbon Steels: Tihe Zhou1; Hatem Zurob2; Peng Zhang3; Sang Hyun Cho3; 1Stelco Inc.; 2McMaster University; 3Algoma Inc.
    Edge breaks initiating at both edges of steel strip are strain lines/Lüders lines which are unacceptable for surface critical and semi-critical applications. Some steel manufacturers are using de-gassing technology by producing interstitial-free steel to reduce or eliminate edge breaks and associated yield-point elongation (YPE). Nonetheless, in low-carbon steel with free interstitials (C, N), it is necessary to develop other approaches to reduce edge breaks and YPE. This paper proposed that heterogeneous grain microstructures can reduce or eliminate YPE in steels containing free interstitials. Heterogeneous grain microstructures can be obtained in two ways during cold-mill processing low-carbon steels: 1) through partially recrystallized microstructure using a low annealing temperature, and 2) creating a bimodal grain-size distribution in a full-recrystallized material. The mechanisms of heterogeneous grain microstructure on the formation of edge breaks/Lüders lines, as well as the effects of chemical composition, reduction ratio and annealing temperatures and mechanical properties are discussed.

Cancelled
M-70: Investigation on the Flow Field of Molten Steel in Ultrahigh-speed Billet Continuous Casting Mold: Pei Xu1; Dengfu Chen1; Peng Liu1; Qinzheng Wang1; Mujun Long1; Huamei Duan1; Jie Yang1; Qimin Wang1; 1Chongqing Universuty
    The mathematical models with coupling with air and without it were established to investigate the flow field of molten steel in ultrahigh-speed billet continuous casting mold with 160×160 mm cross-section. The results show that the casting speed has little effect on flow field pattern, and the flow fields with coupling with air and without it are not much different. Moreover, with the increase of casting speed, the impacting depth and free surface velocity rise, the area of high-speed region augments, level fluctuation is more intense, as well as the wave height enlarges. Although the maximum range of level fluctuation in free surface is ±5 mm and the maximum wave height is 5.654 mm, most level fluctuations are within ±3 mm and the average wave height is less than 3 mm. Therefore, the flow field in ultrahigh-speed billet continuous casting mold is appropriate at current operation parameters.

M-71: Machine Learning Approaches for Prediction Mechanical Properties of Austenitic Stainless Steels: Liping Yang1; Sen Liu2; 1Sichuan University of Arts and Science; 2Colorado School of Mines
    Austenite Stainless steels (ASSs) has been increasingly used in architectural and structural applications since its high corrosion resistance, aesthetic appearance and ease of maintenance. The correlations between functional properties of ASSs and compositions and process parameters are complex and time-consuming to explore. This paper presents mechanical properties data of various compositions of ASSs and processing parameters. It applies machine learning (ML) to ultimate tensile strength (UTS) and elongation datasets for establishing the composition-processing-properties relationships. The importance and correlations of chemical compositions and processing features were analyzed based on mutual information (MI) score and Pearson correlation matrix. The overfitting of training data was prevented using bias-variance trade-off techniques. Results of ML model can achieve prediction accuracy with R2 values over 0.99 for UTS and 0.86 for elongation. The developed model can effectively guide practitioner to prepare most promising chemical compositions, preprocessing and heat treatments for developments of high-performance ASSs.

M-72: Morphological and Thermal Analysis of Peruvian Residues from a Sludge Site of an Integrated Steel Plant: Mery Gomez Marroquin1; Kim Phatti - Satto2; Abraham Terrones - Ramírez2; 1APMMM/UNI; 2UNI
     A characterization of raw materials from a sludge site of an integrated steel in Perú, mainly coarse and fine sludges generated at a primary wet LD de-dusting system, is presented in this work. Chemical analysis, X-ray diffraction, optical and scanning electron microscope, thermal treatment and physical determinations (density and particle size) were utilized. From this characterization the following technological routes were suggested: the production of coarse–fine residues composite briquettes, to be used as burden in ironmaking reactors; and the production of coarse–fine self-reducing briquettes, to be used as an alternative cooling material for the liquid steel temperature control and as burden in reactors demanding fast iron metallization.Keywords: characterization; Linz Donawitz-LD converter sludges; Peruvian residues.

M-73: Numerical Study of Inclusion Removal in Gas Stirred and Electromagnetically Stirred Ladles: Joel Godinez1; Xipeng Guo1; Joshua Vandenoever1; Nicholas Walla1; Armin Silaen1; Chenn Zhou1; 1Purdue University Northwest
    A key part of the steel refining process is the removal of inclusions present within the body of the melt. Generally, these unwanted materials are removed as the product is stirred or mixed, with small scale particles becoming entrained in large scale flow streams and carried towards the surface of the fluid and the side walls of the vessel. In this study, two such stirring methods were simulated on an industry-scale ladle: bottom-blow gas-stirring and electromagnetic stirring. Transient simulations using the population balance method were then performed using the resulting flow fields of the two stirring method simulations. Removal via bubble transport (in the gas-stirred model), wall adhesion, and surface removal reduce the number of inclusions over time. The effectiveness of the two methods is then compared using this resulting inclusion removal rate.

M-74: Ordered Arrangements of BaTiO3 Powders of Cubic Morphologies: Maritza Sanchez1; Olivia Graeve1; 1University of California, San Diego
    Perovskite BaTiO3, among other perovskites, is known to exhibit excellent ferroelectric, dielectric, electro-optic, and elastic properties. This makes it an excellent candidate for use in electronic applications, such as multilayer ceramic capacitors, positive temperature coefficient thermistors, photonic crystals, and pressure transducers. We have worked on synthesizing barium titanate, strontium titanate, and magnesium aluminate in which the powders are shaped as cubes through various synthesis methods and with sizes in the nanometer to sub-micron range. We have analyzed the effects of the synthesis methods on the cubic morphology and composition using electron microscopy and X-ray diffraction. We have also defined a methodology to obtain ordered arrangements of our cubic particles in the form of films, which has allowed an assessment of the role of grain boundaries and diffusion processes on the sintering and grain growth of these materials during calcination treatments.

Cancelled
M-76: Roll Forming of Aluminum 7075-T6 Alloy for an Automotive Bumper Beam: Taekyung Kim1; Geun-Ho Kim1; Sang-Kyo Lee2; Seogou Choi2; Jongsup Lee2; 1Asan Co., Ltd.; 2Korea Institute of Industrial Technology
    Roll forming is a continuous manufacturing process to obtain long parts with constant cross-sections. During the process, sheet metal from coils or pre-cut blanks is plastically bended along a linear axis. Tandem sets of rolls shape the sheet in a series of progressive stages until the designed cross-section is obtained. In automotive industry, the use of aluminum alloys is increasing for lightweight. Various ways are being considered in forming of Aluminum 7075-T6 currently like hot forming, warm forming, w-temper forming Etc. In this study, a cold roll forming process of automotive bumper beam with aluminum 7075-T6 has been developed. By aids of FE analysis, roll forming process are designed. In order to reduce the spring-back and acquire shape accuracy, the roll flower design and roller shape are modified based on the experimental results. Finally, the roll-formed seat rails fulfil required qualities.

M-77: Thermodynamic Properties of Layered Tetradymite-like Compounds of the Ag–Ge–Sb–Te System: Mykola Moroz1; Fiseha Tesfaye2; Pavlo Demchenko3; Myroslava Prokhorenko4; Daniel Lindberg5; Oleksandr Reshetnyak3; Leena Hupa2; 1National University of Water and Environmental Engineering; 2Åbo Akademi University; 3Ivan Franko National University of Lviv; 4Lviv Polytechnic National University; 5Aalto University
    The phase equilibria of the Ag–Ge–Sb–Te system in the part Ag8GeTe6–Ge–GeTe–Sb2Te3 were investigated by the EMF method. According to the experimental data on the EMF versus temperature of the electrochemical cells, the analytical equations of the Gibbs energy were obtained for the GeSb8Te13, GeSb6Te10, GeSb4Te7, GeSb2Te4, Ge2Sb2Te5, Ge3Sb2Te6, and Ge4Sb2Te7 compounds. The thermodynamic properties of silver-saturated tetradymite-like compounds have been calculated for the first time.

Cancelled
M-78: Weld Quality Prediction by a Pattern Recognition Neural Network of the External Appearance Image in the 3rd Generation AHSS Steel Sheets: Munjin Kang1; In-sung Hwang1; Young-Min Kim1; Dongcheol Kim1; 1Korea Institute of Industrial Technology
    This study is to predict the weld quality by a pattern recognition neural network of the externaal appearance image in the 3rd generation AHSS steel sheets. The resistance spot weld appearance image is used as input variable and the nugget diameter, tensile shear strength and fracture mode are used as output variables. The material used was a galvannealed steel sheet with 980MPa grade. The external appearance of weld was filmed by the camera. The images taken were converted to grey images. Its image size was 128*128. The pattern structure was composed of two layers, and the pooling layer was also two layers. Ninety image data obtained from welded specimen under nine welding conditions were studied. As a result, the accuracy of predicting tensile shear strength in the learning data is 99.1% and the coefficient of determination is 0.987. Its accuracy was 98.3% and its coefficient of determination was 0.975.