Papers by Keyword: High-Carbon Steel

Paper TitlePage

Authors: Yi Gil Cho, Young Roc Im, Gyo Sung Kim, Heung Nam Han
Abstract: A finite element model was developed to simulate the deformation, temperature and phase transformation behavior in high carbon steels. The heat capacity of each phase and the heat evolution due to phase transformation were obtained from the thermodynamic analysis of S45C, 50CrV4 and SK85 steels. Phase transformation kinetics of the steels were derived from continuous cooling experiments. An additivity technique was applied to a modified Johnson-Mehl-Avrami equation to analyze continuous cooling curve. To predict the strain due to TRansformation Induced Plasticity (TRIP), a variant selection model for diffusionless transformation and an accelerative creep model for diffusional transformation were adopted. In order to calculate the deformation behavior, the elastic strain, the volumetric strain due to thermal contraction and phase transformation, the plastic strain and the TRIP strain were taken into account. Using the finite element model developed in this study, the temperature-phase-deformation behavior of the high carbon steels was calculated.
Authors: Yasuhiro Morizono, Seiichiro Nakatsukasa, Minoru Nishida
Abstract: Ti-Sn binary alloys (Ti-5 to 20 mol% Sn) were diffusion-bonded to high carbon steel between 1073 and 1273 K for 3.6 ks in a vacuum to investigate the influence of the alloy composition on the interfacial microstructures. Ti-5 and 10 mol% Sn alloys were attached firmly to the steel at a bonding temperature of 1273 K. A continuous TiC layer was formed along the interface, while voids were observed between the TiC layer and the steel. Although the joints with Ti-15 and 20 mol% Sn alloys were also prepared at 1273 K, these joints separated near the interface after the bonding treatment. The TiC layer was formed in the separated surface of Ti-Sn alloy, and Fe in the steel diffused into the Ti-Sn alloy. This indicates that the Ti-15 and 20 mol% Sn alloys established contact with the steel at elevated temperatures until just before the separation. The specimens bonded at 1173 K also denoted the same tendency. However, the Ti-15 mol% Sn/steel joint bonded at 1073 K showed a shear strength of more than 50 MPa. The mechanism and the application of the interface separation are discussed on the basis of the microstructural observations.
Authors: Chang Rong Li, Zhen Yao, Zhao Hua Liang
Abstract: Continuous casting process parameters such as casting speed, superheat, secondary cooling water flow rate have greatly affections to central defects in SWRH82B billet. These parameters were investigated by the methods of chemical content analysis and etch test for macrostructure in some steel plant of china. The results shows that the central defect of SWRH82B billet can be improved when the superheat is controlled at the range of 15~25°C, casting speed is 1.80m•min-1 and secondary cooling water flow rate is 0.72 L•kg-1.
Authors: Sherif Ali Abd El Rahman, Ahmed Shash, Mohamed K. El-Fawkhry, Ahmed Zaki Farahat, Taha Mattar
Abstract: Medium-carbon, silicon-rich steels are commonly suggested to obtain a very fine bainitic microstructure at a low temperature slightly above Ms. Thereby, the resulted microstructure consists of slender bainitic-ferritic plates interwoven with retained austenite. The advanced strength and ductility package of this steel is much dependent on the fineness of bainitic ferrite, as well as the retained austenite phase. In this article, the aluminum to silicon ratio, and the isothermal transformation temperature have been adopted to obtain ultra-high strength high carbon steel. Optical and SEM investigation of the produced steels have been performed. XRD has been used to track the retained austenite development as a result of the change in the chemical composition of developed steels and heat treatment process. Mechanical properties in terms of hardness and microhardness of obtained phases and structure were investigated. Results show that the increment of aluminum to silicon ratio has a great effect in promoting the bainitic transformation, in tandem with improving the stability and the fineness of retained austenite. Such an advanced structure leads to enhancement in the whole mechanical properties of the high carbon steel.
Authors: Matteo Caruso, Hector Verboomen, Stéphane Godet
Abstract: The eutectoid transformation of austenite can occur cooperatively (pearlite transformation) or by means of a non-cooperative mode (Divorced Eutectoid Transformation). In the cooperative mode, ferrite and cementite grow together, leading to the typical lamellar microstructure of pearlite. In the non-cooperative mode, spheroidal cementite particles grow directly from the undissolved carbides in the austenite phase. The transformation product is a fully spheroidized microstructure. In this study, the parameters promoting the occurrence of DET in a hypereutectoid steel (austenitization temperature, cooling rate, presence of proeutectoid cementite in the initial microstructure) were investigated. It is shown that low undercooling levels and a homogenous distribution of fine carbides in the austenite promote the DET over the lamellar transformation mode. The spheroidized microstructures produced by DET lead to larger ductilities comparing to those obtained by the lamellar transformation mode.
Authors: An Chao Ren, Yu Ji, Gui Feng Zhou, Ze Xi Yuan
Abstract: Isothermal constant strain rate compression tests on high-carbon steel are carried out under deformation temperation of 850°C, 950°C, 1050°C、1150°C and 1250°C respectively and deformation of 0.7 using the THERMECMASTOR-Z thermal simulator at a strain rate of 1s-1. The austenite grain morphology before and after deformation and the true stress-strain curves during the deformation process are analyzed. The experimental results show that increased deformation temperation can obviously contribute to the grain refinement. And under the same strain rate conditions, as the deformation temperation rises, peak stress will move toward the opposite direction of strain increment,thus the dynamic recrystallization is apt to occur.
Authors: Jie Lie, Cheng Ling Ge, Hai Chuan Wang, Ling Li, Qi Xuan Rui, Guang Wu Tang
Abstract: Effect of ultrasonic treatment time on inclusions in high carbon steel with the addition of pure rare earth Ce was investigated. The results showed that ultrasonic treatment could disperse, refine and remove inclusions in molten high carbon steel with rare earth. With the increase of ultrasonic treatment time, total oxygen content of high carbon steel and average diameter of inclusions decreased evidently, inclusions in high carbon steel could be removed in a certain degree, but the number of the inclusions increased significantly. Total oxygen content (mass fraction) of high carbon steel, equivalent number I and average diameter d of inclusions in ingot was respectively 59×106, 134 entries•mm-2 and 2.91 μm when the ultrasonic treatment time was 60 s, at the same time, the percentage of inclusions with diameter D<2.31 μm is up to more than 43 % of the total.
Authors: Cheng Jun Liu, Hong Liang Liu, Chun Long Li, Mao Fa Jiang
Abstract: The effects and mechanism of cerium, lanthanum and cerium-lanthanum alloys on microstructure and the impact toughness of high-carbon steel were studied in the present work. For high-carbon steel, the state and the content of RE were measured, and the effects and the mechanism of RE on sulfide inclusions, microstructure and the impact toughness of steel were determined. With increasing the RE addition, the sulfide inclusion can be changed from strip-like, spindle, ellipsoidal and spheric in shape. Strip-like sulfide disappears in high-carbon steel with the RE addition being 0.05%. A small quantity of RE can fine the austenitic grain, decrease the height of the SKK peak of the internal friction curve, and improve the impact toughness of high-carbon steel evidently. And the effects of lanthanum on fining the austenitic grain and improving the impact toughness is the largest, next to that of cerium-lanthanum alloys, and that of cerium is the least, which can be verified by the internal friction experiments.
Authors: Attila Magasdi, János Ginsztler, János Dobránszky
Abstract: The high-carbon steel strips are one of the most widely used base materials of bandsaw blade manufacturing. These materials have sufficient strength and ductility to cope with the high fatigue load of the bandsaw blades. These endless strips are produced by welding, and therefore the weld and the heat affected zone have different mechanical properties, like tensile strength and fatigue resistance, than the base material. These properties of the weld can be influenced by preheat and post weld heat treatment. Regarding to the latest industrial requirements, the application of laserbeam welding was examined to produce higher standard bandsaw blade. The laserbeam welded joints has lower heat input and narrower heat affected zone compared to metal inert gas (MIG) welding, which is currently used in bandsaw blade manufacturing. To assure the proper mechanical properties and sufficient resistance to fatigue, an examination was carried out to determine the effect of preheat temperature and post weld heat treatment time on the mechanical properties and fatigue behaviour of the laserbeam welded joint.
Authors: Attila Magasdi, János Dobránszky, F. Tusz, János Ginsztler
Abstract: The typical tool steels of the wood-cutting industry are the unalloyed and chromium and nickel containing, low-alloyed eutectoid steels. These materials, in tempered condition have a very high, 1200-1400 MPa tensile strength. One of the major failure forms of these tools is the fatigue fracture of the tool. The high pretension and the cyclic load, caused by the cutting and the bending of the tool, easily can cause high-cycle fatigue fracture, especially at the welded area and at the heat affected zone. Thus, one of the most critical part in the manufacturing process of the bandsaw blade is the welding. We have examined the fatigue properties of three types of joints: conventional and cold wire TIG welding, MIG welding, and resistance-butt welded joints. The structure at the weld and at the heat affected zone could highly affect the life-span of the tool. Therefore the welding parameters (preheat, post welding heat treatment (PWHT), shield gas, backing gas), affecting the microstructure of the weld, also have serious affects on the fatigue properties. The influence of welding parameters on the fatigue properties were examined by low-cycle fatigue test.
Showing 1 to 10 of 25 Paper Titles