Microstructure Of Low Carbon Steel Research Articles

The corrosion behavior of low carbon steel (AISI 1010) influenced by grain size through microstructural mechanical

Low-carbon steel (AISI 1010) is the predominant material used in industrial food processing equipment. Such equipment is vulnerable to the corrosive environment produced by various production stages. Different processes, such as sulphonation and carbonation, are used in the processing of sugar in the sugar industry, creating a corrosive atmosphere. The corrosion behavior of low carbon steel (AISI 1010) is strongly influenced by grain size variations, which in turn affect the microstructural mechanical properties of the material. The mechanical behavior and performance of metallic materials, including their corrosion resistance, is determined by grain size which is an important parameter for this phenomena. The impact of low-carbon steel (AISI 1010) microstructure on corrosion behavior is discussed in this work. Heat treatment produces two different types of microstructure from the same material, which are then analyzed. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) have both been used to study characteristics including morphology and content. By supplying an appropriate corrosive medium, the corrosion performance of several microstructures of low-carbon steel (AISI 1010) was assessed, and corrosion rates were calculated using weight-loss and electrochemical techniques. Results show that the creation of a protective coating with a higher charge transfer resistance is caused by the adsorption process. The variety in phases and grain sizes may contribute to the corrosion stability of different microstructures, and as a result, the corrosion rate lowers as average grain sizes are reduced. Employing the galvanic effect, pearlite increases the rate of ferrite corrosion. The study's findings support the notion that quenching low-carbon steel (AISI 1010) results in a finer grain structure and greater corrosion resistance.

Effect of Temperature and Cycle Spheroidizing on Mechanical Properties and Microstructure of Low Carbon Steel

Steel produced by PT. Krakatau steel is the most used product in construction applications to compete with the other structural steel and have the minimum standard. PT. Krakatau Steel produced the steel with 0.08% carbon as JIS 3302 grade SGC 400 standards, resulting in low yield and tensile strength. This study aims to investigate the effect of temperature and the number of cycle spheroidizing on mechanical properties and microstructure. Steel with 0.08% carbon heated at 580, 650, and 720 °C for 6 minutes each cycle (3 cycles) and subsequently cooled by forced air with a 3 °C/s cooling rate. At a temperature of 580 °C on cycles 1, 2, 3, and 650 °C in the third cycle 3, resulting in mechanical properties that meet the JIS G 3302 grade SGC 400 standards.

WAAM Technique: Process Parameters Affecting the Mechanical Properties and Microstructures of Low-Carbon Steel

This study surveys the influences of travel speed, voltage, and intensity on the characteristics of low-carbon steel samples generated by the Wire Arc Additive Manufacturing (WAAM) technique. The results indicated that the WAAM samples have isotropy grain shape, with grain size number values varying from about 8 to 12. Interestingly, the WAAM sample achieves better mechanical properties with a higher ultimate tensile strength (UTS) value and higher elongation at break value than the original wire. The UTS value of the WAAM sample is 21–40% higher than the original steel wire. The WAAM sample with a travel rate of 350 mm·min−1, a voltage of 24 V, and an electrical intensity of 120 A reaches the highest UTS value of 694 MPa. The WAAM sample with a travel rate of 400 mm·min−1, a voltage of 22 V, and an electrical intensity of 170 A gains the lowest UTS value of 599 MPa. Moreover, the elongation values oscillate around 41–57%, two or three times higher than the original steel wire. SEM microstructure reveals a ductile fracture surface with dimples of the samples after the tensile test, indicating the toughness of the samples. The fracture surface also shows the equiaxial shape and grain size of the WAAM samples. According to Taguchi analyses, the travel rate factor greatly impacts grain size. The voltage factor has the highest effect on the UTS value. The intensity factor has the most significant impact on the elongation value.

PENGARUH POSISI SHIELDED METAL ARC WELDING (SMAW) GERAK SPIRAL KAMPUH V TERHADAP KEKUATAN TARIK DAN STRUKTUR MIKRO BAJA KARBON RENDAH

The purpose of this study was to determine the relationship between the position of shielded metal arc welding (SMAW) with spiral motion V on the tensile strength and microstructure of low carbon steel. The research was conducted by welding V-coated low carbon steel with horizontal 2G, vertical 3G and overhead 4G. The test results show that the welding position does not have a significant effect on the tensile strength of low carbon steel welds, where the 3G vertical position provides a higher tensile strength value than the 2G horizontal position and 4G overhead. The microstructure of acicular ferrite (AF) in the vertical position looks dominant uniformly and tightly.

Analysing strength, hardness and grain-structure of 0.2%-C steel specimens processed through an identical heating period with different continuous transformation rates

The present work deals with improvement of mechanical properties and refining the microstructure of low carbon steel (0.2%-C) after applying heat treatment techniques. For the purpose, five different samples were taken under study. First sample was kept in ‘as received’ condition and other four samples were undergone into heating process in an Induction furnace. The holding temperature of all the four samples were kept common i.e., 850 °C for a fixed period of 2.5 h. Then, these four samples were cooled into four different cooling media i.e., Air, Water, Oil, and Furnace. All the samples were in the form of rods with 195 mm length and 32 mm diameter. The universal testing machine was used to determine the tensile strength of all the samples. Rockwell hardness tester was used to find the hardness of samples. The microstructural variation was analysed through an optical microscope. All the results were analysed and compared with ‘as received’ sample. The Oil cooled sample showed the highest tensile strength of 585 MPa. The microstructural orientation of oil cooled sample i.e., bainite + fine lamella of ferrite and cementite, provides a good hardness, strength, and toughness to the steel. In addition, XRD and fractography analysis of the samples were also carried out.

Characterization of hierarchical lath martensite microstructure in low carbon steels using ultra-high voltage TEM and SEM-EBSD analysis

Lath martensite is a heterogenous microstructure in low carbon steels and plays an important part in microstructure for the high strength steels. The complex martensitic structure has been clarified as the hierarchical block and packet structures using SEM observations and electron backscatter diffraction (EBSD) analysis. As the result of variant analysis, it is found that the block consists of sub-blocks and the block size and distribution seem to be new key factors to control the mechanical properties. Each block is further subdivided by laths, which are the finest structural units in lath martensite. The morphology of laths and their variants in low carbon steels has been further investigated using the ultra-high voltage TEM (UHVEM) with 3MeV in accelerated voltage. Based on a comparison of UHVEM and SEM observations for the same field of view, it is found that the laths have a further hierarchical organization with twinned morphology and the fragmented structure within the laths. Two plane crystal analysis of the twin in a lath has been carried out using SEM-EBSD analysis after Xe-FIB large area fabrication process, resulting in the identification of the twin morphology such as the {112} twin plane perpendicular to the {110} habit plane and along the <111> direction. Although several types of twinned morphology such as the long and short length are observed in the lath microstructure under TEM observations, the twinning structure observed in various forms is explained by a simple model in the present study.

The deformation behavior of the gradient nanostructured microstructure of low-carbon steel under the tensile stress

A microstructure within the gradient structure was successfully prepared using the ultrasonic impact treatment (UIT), achieving good strength to toughness synergy. Specifically, the diffraction peak on the surface of the gradient microstructure had a certain broadening effect. Furthermore, the grain size in the gradient deformation layer with a thickness of about ∼150 μm was coarsened from about 100 nm in the top layer (∼10 μm) to about 10 μm in the matrix layer (∼250 μm). Meanwhile, the tensile strength and yield strength of the sample after the UIT were increased by 12.1% and 60.0% respectively. This result was mainly attributed to the fact that the gradient structure could inhibit strain localization in tensile deformation, improving the mechanical properties through the synergistic effect of surface strengthening and bulk toughness. Digital image correlation (DIC) technology was used to observe the displacement characteristics of the sample during the tensile deformation process and the strain change near the fracture. The results showed that the gradient layer could disperse the stress and inhibit the strain localization. The geometrically necessary dislocation (GND) density of the GNS sample after tensile fracture was lower than that of the original sample.

Pengaruh waktu tahan pack carburizing dan penggunaan media quenching cane molasses terhadap sifat mekanik dan struktur mikro baja karbon rendah

Pack carburizing is one of the methods used to increase the carbon content in steel by using solid media. In this study, the addition of carbon elements was carried out using teak wood charcoal and cow bone powder, after that in quenching using cane molasses. Variations used for holding time are 2 hours, 4 hours, and 6 hours, variations in cane molasses content used 10%, 20%, 30%, and the percentage comparison between cow bone powder and teak wood charcoal is 50%:50%. The results of this study show that the pack carburizing resistance time factor is more influential on the mechanical properties and microstructure of low carbon steel. The highest hardness value is found at a holding time of 6 hours with quenching cane molasses 20% of 799.95 kg/cm 2 and the lowest hardness value is found without treatment of 162.62 kg/cm 2 . For the highest impact toughness is found without treatment of 2.02 Joule/mm 2 and the lowest impact toughness value is found at holding time of 6 hours with quenching cane molasses 20% of 1.12 7 Joule/mm 2 . For microstructures formed after treatment, martensite structures are formed due to rapid cooling.

Effect of hydrogen on evolution of deformation microstructure in low-carbon steel with ferrite microstructure

In this study, the deformation microstructure of hydrogen-charged ferritic-pearlitic 2Mn-0.1C steel was characterized using SEM-BSE, SEM-EBSD, TEM, and neutron diffraction. The microscopic mechanism of hydrogen-related quasi-cleavage fracture along the {011} planes was also discussed. It was found that hydrogen increased the relative velocity of screw dislocations to edge dislocations, leading to a tangled dislocation morphology, even at the initial stage of deformation (e = 3%). In addition, the density of screw dislocations at the later stage of deformation (e = 20%) increased in the presence of hydrogen. Based on the experimental results, it is proposed that a high density of vacancies accumulated along {011} slip planes by jog-dragging of screw dislocations, and coalescence of the accumulated vacancies led to the hydrogen-related quasi-cleavage fracture along the {011} slip planes.

Effect of Hydrogen on Evolution of Deformation Microstructure in Low-Carbon Steel with Ferrite Microstructure

In this study, the deformation microstructure of hydrogen-charged ferritic-pearlitic 2Mn-0.1C steel was characterized using SEM-BSE, SEM-EBSD, TEM, and neutron diffraction. The microscopic mechanism of hydrogen-related quasi-cleavage fracture along the {011} planes was also discussed. It was found that hydrogen increased the velocity of screw dislocations, leading to a tangled dislocation morphology, even at the initial stage of deformation (e = 3%). In addition, the density of screw dislocations at the later stage of deformation (e = 20%) increased in the presence of hydrogen. Based on the experimental results, it is proposed that a high density of vacancies accumulated along {011} slip planes by jog-dragging of screw dislocations, and coalescence of the accumulated vacancies led to the hydrogen-related quasi-cleavage fracture along the {011} slip planes.

Fractal model of structure-properties effect of low carbon steel

Fractal theory has been used for predicting of microstructure (ferrite, pearlite and non-metallic inclusions) effect on mechanical properties (KCV60, a0.2, crB, S) of S355J2 steel. The fractal model which has been obtained may be considered as additive database. The database can be complemented by different treatment modes and microstructure. It has been stated that good response of structure-properties has been obtained for strength characteristics (a0.i crB) of S355J2 steel and fractal size of lamellar pearlite. Also, correspondence of elongation to fractal size of ferrite has been obtained. As it has been determined the better correspondence of fractal size of non-metallic inclusions defined to impact toughness of S355J2 steel. The results have been confirmed by effect of low carbon steel microstructure on mechanical properties of the steel. The histogram of microstructure and non-metallic inclusions effect on mechanical properties of S355J2 steel has been plotted.

Effects of Heat Treatment on Mechanical Properties and Microstructure of Low Carbon Steel ‘Ferrium C64’

Effects of Heat Treatment on Mechanical Properties and Microstructure of Low Carbon Steel ‘Ferrium C64’

Effects of thread rolling processing parameters on mechanical properties and microstructures of high-strength bolts

Abstract Bolt production with a grade of 10.9 class quality made from AISI4140 material with a low thread rolling index is usually implemented in accordance with the thread rolling method (cold forming) in industrial applications. In this method, the effects of die revolutions and multiple passes are unknown in the thread forming process as the devices are usually operated with respect to geometrical dimensions but not the mechanical properties and microstructures of the material. In the literature there are few studies on microstructures of low-carbon steel having a higher thread rolling index in bolt production. This study experimentally examined the effects of the processing parameters on the mechanical properties and microstructures. Parameters such as forming speed and single or multi-pass influences were considered in the production of M12 × 1.75 and M20 × 2.5 fasteners widely used in industrial applications. The experiments identified the behavior of the mechanical properties, microstructures and micro-hardness of the AISI4140 material at two forming speeds (rpm) and three passes in the thread rolling process. Thus, significantly sensible outcomes as a function of processing parameters were obtained considering the thread strength viewpoints.

Unsupervised microstructure segmentation by mimicking metallurgists\u2019 approach to pattern recognition

An efficient deep learning method is presented for distinguishing microstructures of a low carbon steel. There have been numerous endeavors to reproduce the human capability of perceptually classifying different textures using machine learning methods, but this is still very challenging owing to the need for a vast labeled image dataset. In this study, we introduce an unsupervised machine learning technique based on convolutional neural networks and a superpixel algorithm for the segmentation of a low-carbon steel microstructure without the need for labeled images. The effectiveness of the method is demonstrated with optical microscopy images of steel microstructures having different patterns taken at different resolutions. In addition, several evaluation criteria for unsupervised segmentation results are investigated along with the hyperparameter optimization.

Effects of thread rolling processing parameters on mechanical properties and microstructures of high-strength bolts

Abstract Bolt production with a grade of 10.9 class quality made from AISI4140 material with a low thread rolling index is usually implemented in accordance with the thread rolling method (cold forming) in industrial applications. In this method, the effects of die revolutions and multiple passes are unknown in the thread forming process as the devices are usually operated with respect to geometrical dimensions but not the mechanical properties and microstructures of the material. In the literature there are few studies on microstructures of low-carbon steel having a higher thread rolling index in bolt production. This study experimentally examined the effects of the processing parameters on the mechanical properties and microstructures. Parameters such as forming speed and single or multi-pass influences were considered in the production of M12 × 1.75 and M20 × 2.5 fasteners widely used in industrial applications. The experiments identified the behavior of the mechanical properties, microstructures and micro-hardness of the AISI4140 material at two forming speeds (rpm) and three passes in the thread rolling process. Thus, significantly sensible outcomes as a function of processing parameters were obtained considering the thread strength viewpoints.

TEM Study of Junctions between Martensite Laths and Changes in Microstructure of Low-Carbon Steel before LCF II

The joining points between martensite packets (laths) and their microstructure in low-carbon martensitic steel were TEM studied. In order to determine the real microstructure of the packet, martensite examinations were conducted before low-cycle fatigue (LCF) tests, considering the structure of the packets and types of their joining. The changes in microstructure occurred in the above places after austenite-martensite transformation were also analyzed. It was shown that after jointing some packets initiate arch-like contours in the laths, exhibiting a presence of local stresses. Several types of joints are considered, including the penetration of laths of one packet into that of neighboring one. It was revealed that the microstructure changes are exhibited in joining points without any external deformation, and result in the localized plastic deformation at LCF. It is assumed that microcrack initiation and commencement of fatigue failure of the material should be expected to happen just in these areas. All the above is explained from point of view of the peculiarities of martensitic transformation.

Metallurgical Characterization of a Low Carbon Steel Microstructure Using Linear and Nonlinear Ultrasonics

In this study, linear and nonlinear ultrasonic (UT) methods are utilized to evaluate the microstructures of A572 low carbon steel samples that were intercritically heat-treated at three temperatures and quenched to room temperature. The microstructures were also qualitatively and quantitatively assessed using standard metallography. ImageJ software was used to measure the amount of the phases. Correlations between ferrite content and linear velocity and the acoustoelastic coefficient are established. The experiments show that the UT linear and nonlinear velocities are affected by varying the amounts of ferrite and martensite. The acoustoelastic coefficient is found to be more sensitive to small changes in ferrite volume fraction.

Phase-field simulation of martensite microstructure in low-carbon steel

We present three-dimensional phase-field simulations of martensite microstructure formation in low-carbon steel. In this study, a full set of 24 Kurdjumov-Sachs symmetry variants of martensite is considered. Three different carbon compositions are investigated in order to reveal the effect of carbon content on the martensite microstructure formation. The simulations are performed using the finite strain framework which allows considering real martensite transformation strains. Using Neuber elasto-plastic approximation to the mechanical equilibrium solution, realistic stresses and strains can be obtained during martensite formation resulting in realistic mechanical driving forces for the transformation. The simulated microstructures are compared to experimental results for three carbon compositions. Good agreement between simulated and experimental results is achieved.

Effect of Nb Addition on the Hot Deformation Behavior and Microstructure of Low Carbon Steel

Industrial trials for hot deformation production of low carbon steel with fine ferrite grains were carried out. The different hot rolling parameters including the amount of strain and strain rate at each of six rolling stands as well as the final deformation temperature were designed to produce the required microstructure. Two types of low carbon steels, with/without Nb-addition, were used in this study to evaluate the effect of Nb addition. Stress induced grain refinement has been successfully achieved, aided by Nb, resulting in an average grain size of 4µm following the coiling process. The flow stress calculated at each of the six stands was used to follow the structure evaluation during processing.

Corrosion properties of low carbon steel prepared by submerged friction stir processing

Submerged friction stir processing (SFSP), that is, the entire process was carried out underwater, was successfully conducted on low carbon steel. The microstructure, electrochemical corrosion, and salt fog corrosion properties of SFSP low carbon steel were investigated. The results indicated that phase transformation and dynamic recrystallization occurred during SFSP and finally resulted in a dual phase fine grain microstructure in the processed zone (PZ), which consisted of ferrite and homogenous martensite phase. The grain size of ferrite was refined to 5.7 µm, and the width of martensite phase was 650 nm, respectively. In addition to changing the microstructure of low carbon steel, SFSP could also affect its corrosion property. SFSP samples exhibited better resistance against electrochemical corrosion and salt fog corrosion than BM samples. The reason was that, grain refinement and martensite formation induced by SFSP were conducive to forming dense protective layer, which effectively hindered the electrochemical corrosion and salt fog corrosion of the SFSP low carbon steel.