Investigation of Three-Dimensional Geometry of Butterfly Martensite and Analysis of Relationship between Hardness of Lath/Butterfly Two-Phase Martensite and its Grain Thickness in Medium-Carbon Steel

2021 ◽  
Vol 1016 ◽  
pp. 1039-1044
Author(s):  
Takayoshi Niho ◽  
Keisuke Nagato ◽  
Masayuki Nakao
Keyword(s):  
Carbon Steel ◽  
Ion Beam ◽  
Lath Martensite ◽  
High Carbon Steel ◽  
Three Dimensional ◽  
Medium Carbon Steel ◽  
Thin Plates ◽  
Low Carbon ◽  
Two Phase ◽  
Medium Carbon

Medium-carbon steel with approximately 0.6 wt% carbon is widely used for mechanical applications, because the martensite contained in it is harder than that of low-carbon and high-carbon steel. The microstructure of steel martensite varies depending on the carbon content, and the microstructure of medium-carbon steel martensite are a mixture of lath martensite (LM) and butterfly martensite (BM). The geometry of LM grains are thin plates having thicknesses of 0.2–0.5 μm. As for BM, some researches demonstrated that the region of martensite spreads in the depth direction of the observation surface. However, the three-dimensional geometry of BM grains remains unclear. Through cross-sectional observation using focused ion beam (FIB), the present study demonstrates that one BM grain is formed via collision of two plates. Previous research shows that the hardness of LM is inversely correlated with the thickness of the grains. The FIB observation result indicates that geometry of LM and BM grains are both plate-like. In the present study, whether the same relationship is valid for the mixture of LM and BM grains is investigated. The results show that the hardness of medium-carbon steel martensite increases according to the decrease in thickness of constituent grains of the two-phase structure of LM and BM.

Pengaruh Teknik Tempa Lipat Terhadap Perubahan Sifat Mekanik Material AISI O1 Pada Pembuatan Pisau Tanto

2021 ◽  
Vol 1 (1) ◽  
pp. 51
Author(s):  
Alfan Ekajati Latief ◽  
Syahril Sayuti ◽  
Rakean Wide Windujati
Keyword(s):  
Heat Treatment ◽  
Carbon Steel ◽  
Treatment Process ◽  
Lath Martensite ◽  
High Carbon Steel ◽  
Medium Carbon Steel ◽  
Raw Material ◽  
High Carbon ◽  
Micro Structure ◽  
Medium Carbon

 ABSTRAKTanto merupakan senjata tajam yang berasal dari Jepang dan merupakan senjata kedua bagi para Samurai di Jepang. Tanto biasa terbuat dari baja karbon menengah hingga baja karbon tinggi yang. Material baja yang digunakan untuk pembuatan Tanto dalam penelitian ini adalah baja AISI seri O1 karena memiliki karakteristik sifat mampu bentuk yang baik serat dapat dikuatkan melalui proses heat treatment. Material baja ini dibuat dengan proses tempa lipat  dengan variasi tempa empat lipatan dan satu lipatan. Pembuatan Tanto dan spesimen uji dilakukan dengan proses tempa lipat secara konvensional menggunakan tungku arang, dengan temperatur tempa rata-rata yaitu ±1200oC, kemudian dilanjutkan dengan quenching pada temperatur ± 850oC, serta tempering pada temperatur ±250oC. Penelitian ditujukan untuk mengetahui pengaruh dari proses tempa empat lipatan dan tempa satu lipatan terhadap sifat mekanik, yaitu kekerasan dan kekuatan impak serta untuk melihat perubahan pada struktur mikro. Hasil pengujian menunjukkan bahwa nilai kekerasan paling tinggi sebesar41HRC yang dimiliki oleh pada raw material, ,sedangkan nilai impak paling tinggi sebesar 224,02 Joule/cm² ayng dicapai oleh material dengan proses tempa empat lipatan, Fasa akhir yang ditemukan pada baja tempa empat lipatan adalah  bainit dan martensit, sementara  perlit dan ferit ditemukan  pada baja satu lipatan, dan lath martensit ditemukan pada pada raw material  Kata kunci: Pisau Tanto, Tempa lipat ,Quenching, Tempering, Uji Impak  ABSTRACT Tanto is a sharp weapon originating  from Japan and is the second weapon for Samurai in Japan. Tanto is usually made of medium carbon steel to high carbon steel. The material which is used in this research is AISI O1 series steel because of its high ability to be formed and also can be made tough through a heat treatment process. This steel is made by folding forge process, with variation in number of folding, which is 4 folds and 1 fold. The making of Tanto and test specimens was carried out by conventional fold forging processes by using a charcoal furnace, with an average forging temperature at ± 1200oC, continue with quenching at ± 850oC, and tempering at ± 250oC. The research is carried out in order to determine the effect of the four-folds forging and one-fold forging to the mechanical behavior, which are hardness and impact strength,  and also to see change in its micro structure. The test that have been carried out shows that the highest hardness value of 41 HRC owned by raw material, while the highest impact value of 224.02 Joules / cm² obtained by material with four layer forging process. Final phases that found in the four-fold forged steel are bainite and martensite, pearlite and ferrite found in one-fold forged steel. and lath martensite in found in the raw material. Keywords: Tanto Knife, Folding Forging, Quenching, Tempering, Testing, Impact Tests

Morphology and Formation Mechanism of Martensite in Steels with Different Carbon Content

2011 ◽  
Vol 201-203 ◽  
pp. 1612-1618 ◽  
Author(s):  
Yun Ping Ji ◽  
Zong Chang Liu ◽  
Hui Ping Ren
Keyword(s):  
Electron Microscope ◽  
Carbon Steel ◽  
Carbon Content ◽  
Formation Mechanism ◽  
Lath Martensite ◽  
High Carbon Steel ◽  
Volumetric Strain ◽  
Medium Carbon Steel ◽  
Plate Martensite ◽  
Low Carbon

0MnVTiNb, 12Cr1MoV, 20Cr2Ni4, 35CrMo, 40Cr, 42CrMo, 60Si2CrV and T8 steels and Fe-1.2C alloy were used to study the morphology and formation mechanism of martensite by metallographic microscope, QUANTA-400 environmental scanning electron microscope and JEM-2100 transmission electron microscope after they were austenized at different temperature and then quenched respectively. The results show that the martensite of low-carbon steel is lath martensite, the martensite of high-carbon steel is plate martensite, and the martensite of medium-carbon steel is the integrated microstructure of lath martensite and plate martensite. With the increase of carbon content, the morphology of martensite in steel evolves from lath shape to plate shape, the distribution of martensite slices changes from in parallel to with crossing angle, and the substructure evolves from high density dislocations and stacking faults to twin crystals. The martensite in steel can nucleate in the austenite crystal grain interior as well as along the austenite crystal grain boundary. It is proposed that the volumetric strain energy in martensite transformation is the essential reason of the different morphologies of martensite.

Heat Treatment Recycling of Dual Phase Region and its Effect on Hardness, Microstructure and Corrosion Rate of Medium Carbon Steel

2014 ◽  
Vol 909 ◽  
pp. 100-104
Author(s):  
Mohamed A. Gebril ◽  
M.S. Aldlemey ◽  
Farag I. Haider
Keyword(s):  
Heat Treatment ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Phase Region ◽  
Medium Carbon Steel ◽  
Dual Phase ◽  
Two Phase ◽  
Medium Carbon ◽  
The Third ◽  
Hardness Increase

In this work, the investigations were carried out to study the effect of heat treatment at dual phase of austenite and ferrite on mechanical properties , microstructure and corrosion rate of low alloyed medium carbon steel. The specimens were divided into five groups, first group, specimens were heated to the duel phase region at temperature of 740°C soaked for 30 minutes and quenched in water. The second group, The specimens were heated to 740°C soaked for 30 minutes and quenched in water, then tempered to 480°C soaked for 20 minutes. The third group the specimens were heated to austenizing temperature of 840°C soaked for 30 minutes and quenched in water, then the specimens reheated to the dual phase region at 740°C, soaked for 30 minutes and quenched in water, then the specimens were tempered at temperature 480°C for 30 minutes. The forth group, the specimens were heated to austenizing temperature of 840°C soaked for 30 minutes and quenched in water, this process were repeated again before the specimens were thereafter heated to the dual phase region at temperature of 740°C, soaked for 20 minutes and quenched in water, then the specimens were tempered at temperature 480°C for 20 minutes. The fifth group, the specimens were heated to austenizing temperature of 840°C soaked for 20 minutes and quenched in water, this process were repeated two times again before the specimens were thereafter heated to the dual phase region at temperature of 740°C, soaked for 20 minutes and quenched in water, then the specimens finally tempered at temperature 480°C for 20 minutes. The results proved the hardness increase after heat treatment at first and second group, at third group the highest hardness value was due to formation of martensite and ferrite, but at fourth and fifth groups hardness decreases due to appearance of carbides particles, also corrosion rate usually increases with two phase at microstructure than stable one phase, third group have less corrosion rate than fourth and fifth due to carbides particles formation which lead to more corrosion rate due to three phases presents.

scholarly journals Revealing the Unexpected Two Variant Pairing Shifts Due to Temperature Change in a Single Bainitic Medium Carbon Steel

2021 ◽  
Author(s):  
Adam Ståhlkrantz ◽  
Peter Hedström ◽  
Niklas Sarius ◽  
Annika Borgenstam
Keyword(s):  
Carbon Steel ◽  
Electron Backscatter Diffraction ◽  
Low Carbon Steel ◽  
Medium Carbon Steel ◽  
Low Carbon ◽  
Medium Carbon ◽  
Strong Relation ◽  
Upper Bainite ◽  
The Common ◽  
Backscatter Diffraction

AbstractThe microstructure of a low alloy medium carbon bainitic steel, austempered in the temperature range 275 °C to 450 °C has been investigated by detailed electron backscatter diffraction and variant pairing analysis. It is observed that the variant pairing tendency has two distinct changes with varying temperature. At low temperature V1-V6 is the most frequent, whereas V1-V2 is the most frequent at intermediate temperature and at the highest temperature, V1-V4 dominates. This is distinct from the literature on low carbon steel where only two dominant variants pairs, related to the common distinction of bainite into lower and upper bainite, are typically reported. The change of the variant pairing in bainite also has many similarities with the change of variant pairing in martensite when its carbon content changes. Another observation is that the morphological orientation of cementite in the bainite has a strong relation with the variant pairing at lower austempering temperatures.

Application of Rietveld Refinement and Williamson Hall Analysis in Ultra-Low Carbon to High Carbon Steels

2019 ◽  
Vol 969 ◽  
pp. 3-8
Author(s):  
Soumya Sourav Sarangi ◽  
Avala Lavakumar
Keyword(s):  
Carbon Steel ◽  
Dislocation Density ◽  
Rietveld Refinement ◽  
Carbon Concentration ◽  
High Carbon Steel ◽  
Low Carbon Steel ◽  
Lattice Parameter ◽  
Medium Carbon Steel ◽  
Low Carbon ◽  
High Carbon

Current study deals with the microstructural characterization of five different plates of steel with carbon concentration ranging from ultra-low to moderately high. Phase analysis was carried out using XRD technique. The XRD results were analyzed through Rietveld refinement and Williamson Hall plots. Rietveld refinement was carried out to understand the effect of carbon concentration on the lattice parameters of the above steel samples in as-received condition and also after deformation under uni-axial tensile loading. Lattice parameters obtained from refinement showed the strong dependence on carbon concentration of the given steels. But the failed specimens showed somewhat complex results as Spheroidized high carbon steel, Low carbon steel and IF steel showed an increase in lattice parameter whereas Medium carbon steel and Microalloyed steel showed a contraction in lattice parameter. Williamson Hall plot gave the crystallite size, microstrain and dislocation density in the steels. For IF and Microalloyed steels the dislocation density in the material is found to be higher after deformation whereas dislocation density decreased in Spheroidized high carbon steel, Medium carbon steel and Low carbon steel.

scholarly journals Effect of Deformation on Microstructure and Mechanical Properties of Medium Carbon Steel During Heat Treatment Process

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Yan Peng ◽  
Caiyi Liu ◽  
Ningning Wang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Carbon Steel ◽  
Heating Temperature ◽  
Lath Martensite ◽  
Medium Carbon Steel ◽  
Medium Carbon ◽  
Experimental Steel ◽  
Microstructure And Mechanical Properties ◽  
Strength And Plasticity

AbstractThe current research of the Q-P and Q-P-T process has been focused on controlling the heating temperature and holding time, or adding alloy elements into the steel to induce precipitation strengthening and improve the strength and plasticity of the steel. In this article, based on a quenching-partitioning-tempering (Q-P-T) process combined with a hot deformation technology, a deforming-quenching-partitioning-tempering (D-Q-P-T) process was applied to medium carbon steel. The effect of the heat treatment parameters on the microstructure and mechanical properties of experimental steel under deformation was studied. Through use of a scanning electron microscope (SEM), transmission electron microscopy (TEM) and tensile tests, the optimal heat treatment conditions for realizing high strength and plasticity that meet the safety requirements were obtained. The mechanism for the D-Q-P-T process to improve the strength and plasticity of experimental steel was discussed. A multiphase composite structure of lath martensite and retained austenite was obtained. Compared with the Q-P-T process, use of the D-Q-P-T process can increase the strength of steel by 57.77 MPa and the elongation by 5%. This study proposes a method to improve the strength and plasticity of steel.

scholarly journals PENGARUH WAKTU KONTAK AIR LINDI DAN UDARA TERHADAP LAJU KOROSI BAJA ST-41 DAN ST-60

JTAM ROTARY ◽  
2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Muhammad Irfan Riyadi ◽  
Rudi Siswanto
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Contact Time ◽  
Atmospheric Corrosion ◽  
Chromium Content ◽  
Low Carbon Steel ◽  
Medium Carbon Steel ◽  
Low Carbon ◽  
Medium Carbon ◽  
Heavy Equipment

The use of metals in the environment is especially important in environments such rubbish in heavy equipment or trucks, especially those of the tailgate is a tool to bring a variety of organic waste and inorganic bring the matter dissolved through a liquid called leachate and make contact or direct contact with the steel so that corrosion occurs due to leachate or wastewater flow contains many corrosive compounds that make part tailgate become quickly corroded. This study aims to determine the bias steel resist corrosion rate. The steel used is steel steel ST-41 and ST-60 is a low carbon steel and medium carbon steel. The methods used in research in the methods of losing weight and observe the types of corrosion that occurs by means of immersion with ASTM G31-72 which vary contact time for 3 weeks. Based on research conducted showed the corrosion rate of the fastest occur in steel ST-60 with a contact time of 1 week soaked the leachate and 2 weeks in contact with the air due to differences in the composition of the steel ST-60 and steel ST-41 which has a chromium content so high that steel ST-41 is superior in resisting corrosion rate while the type of corrosion that occurs is evenly corrosion and atmospheric corrosion.

scholarly journals Microstructure and selected properties of boronized layers produced on C45 and CT90 steels after modification by diode laser

2016 ◽  
Vol 36 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Aneta Bartkowska ◽  
Dariusz Bartkowski ◽  
Damian Przestacki ◽  
Małgorzata Talarczyk
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Diode Laser ◽  
High Carbon Steel ◽  
Medium Carbon Steel ◽  
High Carbon ◽  
Medium Carbon ◽  
Laser Surface Modification ◽  
Study Results ◽  
Diffusion Boriding

Abstract The paper presents the study results of macro- and microstructure, microhardness and corrosion resistance of C45 medium carbon steel and CT90 high carbon steel after diffusion boriding and laser modification by diode laser. It was found that the increase of carbon content reduced the thickness of boronized layer and caused change in their morphology. Diffusion boronized layers were composed of FeB and Fe2B iron borides. As a result of laser surface modification of these layers, the microstructure composed of three areas: remelted zone, heat affected zone (HAZ) and the substrate was obtained. Microhardness of laser remelting boronized layer in comparison with diffusion boronized layer was lower. The presence of HAZ was advantageous, because mild microhardness gradient between the layer and the substrate was assured. The specimens with laser boronized layers were characterized by better corrosion resistance than specimens without modified layer.

Microstructural Evolution during Warm Compression of Medium Carbon Steel Quenched

2008 ◽  
Vol 47-50 ◽  
pp. 853-856 ◽  
Author(s):  
Xin Zhao
Keyword(s):  
Electron Microscopy ◽  
Carbon Steel ◽  
Microstructural Evolution ◽  
Lath Martensite ◽  
Optical Microscope ◽  
Medium Carbon Steel ◽  
High Angle ◽  
Medium Carbon ◽  
Transmission Electron ◽  
Gleeble 3500

In order to produce nano-structured carbon steel, a 0.45%C steel was quenched and warm-compressed on a Gleeble 3500 Machine. The microstructural evolution during the process was studied by using an optical microscope and a transmission electron microscopy. The starting microstructure was lath martensite with a small amount of flake martensite. A lot of high-angle boundaries between martensite laths were induced after 50% reduction compression at 350°C. The microstructure of the specimen compressed at 600-650°C was nano-carbides + equiaxed ultrafine ferrite grains. The mechanism for grain refinement is incomplete dynamic recrystallization.

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