Lateritic Steel Research Articles

Pengembangan Baja Paduan Tahan Peluru Melalui Proses Hot-Forging Terhadap Morfologi Dan Sifat Mekanik

Laterite steel is steel that has a nickel content of up to 2%. The nickel content can produce steel with superior properties such as: high strength, corrosion resistance, and good weldability properties. With the superior nature of laterite steel is needed in the main tool of the indonesian national tantara weapon system. To find out the performance of damage to bulletproof materials, then conducted research on this laterite steel as a tough armour material by conducting research in the form of mechanical properties testing (Hardness, and Impact) and microstructures (Metalography). Samples are prepared in accordance with ASTM standardization. Based on the results of the hardness test, the average values of F and T samples were 663.9 HVN and 170.7 HVN. Material F qualifies as a ballistic resistant material (armour) because the hardness obtained in accordance with the classification and can withstand bullet penetration well. Then the impact test obtained the average value of the F and T samples is 9 joules and 148 joules. For F samples, the type of fault is a granular fracture and a T sample of the type of fault is a tenacious fracture. As a result of metallographics, sample F has a corrected phase is upper bainite as a matrix and martensite is generally shaped like a fine needle. Then the T sample has a formed phase is dominated by ferrite with soft and tenacious properties. As well as perlite as a matrix with quite hard and strong properties.

Analisa Karakterisasi Baja Paduan As-Cast-Fe-Cr-Mn-Mo Dengan Komposisi Nikel Terhadap Sifat Mekanik Dan Struktur Mikro Hasil Uji Balistik

Lateritic steel is a low-nickel steel with a nickel content of 1-4.5 percent. Steel with a high nickel percentage has better qualities like high strength, corrosion resistance, and weldability. This material is commonly used in crushers and grinding machines. This material can also be utilized as an armor material. A study was undertaken to investigate the ability of laterite steel to be employed as armor material by characteristic testing (impact test and hardness test) and microstructure (metallography) of laterite steel. ASTM standards must be followed in the preparation of all samples. The impact test was performed on 9 samples from 3 specimens, with each sample being placed on an anvil and pounded with a pendulum that the average values of samples A, B, and D were 11 J, 9 J, and 12 J, respectively. The fractures were granular, indicating that the material is extremely fragile. The hardness test was then performed using the Vickers method with a 5 Kgf load. The polished sample is placed immediately on a vise, and then a diamond-shaped indenter is attached; the hardness test value is determined by the size of the trace of the indenter, with the average values of samples A, B, and D being 292.63 HVN, 310.47 HVN, and 464.87 HVN, respectively. Microstructure measurements revealed that sample A formed ferrite perlite, sample B formed lower bainite, and sample D formed martensite phase.

Effect of forging load and heat treatment process on the corrosion behavior of A588-1%NI for weathering steel application in a marine environment

The study focused on the effect of forging load and heat treatment on the corrosion behavior of A588-1%Ni weathered steel. The samples used were hot forged steel (A588%-1%Ni) with a load of 50 tons and 75 tons at a temperature of 800-850 °C. The test sample was reheated at an intercritical temperature between A3–A1, around 780 °C, held for 1 hour, and then cooled to room temperature. The cooling media used are water, oil, and open air. Forging loads and heat treatment variation affect the microstructure and corrosion rate of A588-1%Ni. Based on the metallographic test and after the hot forging process, A588-1%Ni laterite steel has a microstructure as ferrite-perlite. Then, after heat treatment as ferrite and cementite-containing phase, pearlite, bainite, or martensite may very well. Cooling water delivers a uniformly distributed lath martensite with an acicular ferrite phase. In addition, the oil media creates bainite with an acicular ferrite phase coarser size. The open-air media produces a pearlite + ferrite phase. Corrosion behavior of laterite steel subjected to hot forging process and followed by heat treatment was evaluated in 3% NaCl solution. Oil cooling with bainite-ferrite microstructure has the lowest corrosion rate, which is 11.96x10-3 mmpy.

STUDY ON THE EFFECT OF COMPOSITION AND VARIATION OF Sn/Zn COOLING MEDIA ON NICKEL ALLOY STEEL THROUGH HOT FORGING AND AUSTEMPERING

STUDY ON THE EFFECT OF COMPOSITION AND VARIATION OF Sn/Zn COOLING MEDIA ON NICKEL ALLOY STEEL THROUGH HOT FORGING AND AUSTEMPERING. Laterite steel with nickel content is expected to be a solution to overcome the lack of domestic steel availability and dependence on imports. This research was conducted to develop Nickel-Chromium-Molybdenum alloy steel used Grinding ball for cement industrial applications. Grinding ball is the one of imported steel products needed to be crushing and size reduction the ores or cement. In addition to import issues, grinding balls have a significant problem: their mechanical properties that do not meet SNI 1049 require the material to have a minimum hardness value of 45 HRC. In this study, the characteristics of Nickel alloy steel were investigated further through heat treatment of forgings heated at the austenitizing temperature of 950 °C and austempering with variations in the cooling medium of Sn/Zn solution. The cooling medium was chosen because it has a melting temperature in the phase diagram area to form the bainite microstructure with complex and challenging characteristics, both of which are required in material for grinding ball applications. In particular, the hardness value that passed the SNI 1069 standard was the use of samples with a Cr-Mo alloy of 1%-wt with a hardness value of 45.92 HRC for Sn Austemper and 48.07 HRC for Zn austemper.

The development of a588 modified laterite steel using thermomechanical and low-temperature tempering process for weather resistant steel

Laterite Steel A-588 has the potential to be a high strength low alloy for Corten steel application. Laterite steel A-588 is developed through a thermomechanical process followed by a tempering process to obtain high strength and corrosion resistance. This study aims to determine the correlation between the addition of nickel content, the variation of the cooling rate during heat treatment to the mechanical properties, and the corrosion resistance of A-588 laterite steel. The Cu, Cr, Ni, P, and Si elements significantly impact microstructure transformation. Laterite Steel A-588 with nickel and thermo-mechanical process variation has been focused on in this research. Laterite steel with 0,42%, 1%, 2%, and 3% nickel varied was homogenized, hot rolled, and heat treated with three cooling variations by water, oil, and air. They are processed with 150 C tempering. Low tempering temperature caused fine carbide precipitation and phase transition of martensite to bainite. This resulted in bainite as the final microstructure, lath tempered martensite, carbide, and ferrite. 3% Ni with a fast cooling rate increased the tempered martensite and bainite phase formation. It allowed the strength and hardness to increase relatively, followed by decreased elongation and corrosion resistance caused by the galvanic reaction. Most optimal of mechanical properties determined at a sample with 2% nickel in a water medium (strength 1203 MPa, elongation 10%, hardness 404 BHN, corrosion rate 1,306 mpy).

Corrosion Behavior of a Predeformed Fe-Ni Lateritic Steel with Bainite Structure

In a railway track for intermodal usage between a train station to a port, an observation on corrosion behavior of the track alloy in the coastal environment needs to be considered. In this study, Fe-Ni lateritic steel with bainite structure is observed. This alloy is developed from lateritic ores in Indonesia as an alternative to the conventionally made Fe-Ni steels. This study aims to determine the effect of cold rolling and austempering processes on the corrosion properties of the alloy. The cold-rolling reductions used are 30% and 70%, followed by an austempering process at 400°C for 30 mins with air cooling. The corrosion test was performed on four different samples-- First, a before deformation sample. Second, 30% and 70% cold-rolled samples. Third, austempered without deformation samples. Besides, fourth, deformed austempered samples. The corrosion test method implemented was the CASS Method for 2, 4, and 6 days. The highest corrosion rate obtained by 30% cold rolling, and the corrosion rate is increased as the austempering addition. The microstructures of rust are approximately porous few compact, near to voluminous coarse-grain corrosion products, and tend to crack.

Pengaruh Variasi Persentase Reduksi pada Proses Pengerolan Panas terhadap Sifat Mekanik dan Struktur Mikro Baja Laterit

Lateritic ore is one of the raw materials for the steel industry. Lateritic ore processed into laterite steel has more advantages than steel in the market. It has better tensile strength, hardness, corrosion resistance, and welding properties. Lateritic steel is made by performing a casting process. This research aims to investigate the effect of reduction percentage on mechanical properties and microstructure of the lateritic steel after the hot rolling process. The specimens were heated to austenitization temperature at 1000 0 C for 1 hour before the rolling process. The reduction percentage varies by 10%, 15%, and 20%. Hardness and impact test was conducted using a Rockwell Hardness and Charpy method. The microstructure was observed using an optical microscope. The results showed the optimum hardness of 58 HRC in a hot rolling sample with 20% reduction. The highest impact strength of 46 Joule and ductile fracture took place in this sample. The microstructure of this sample showed a bainitic phase causing lower hardness.

Effect of Quenching and Tempering on Micro Structure and Mechanical Properties in Laterite Steel

Effect of Quenching and Tempering on Micro Structure and Mechanical Properties in Laterite Steel

The Effect Holding Time Variation on the Process Of Heat Treatment Austempering on Mechanical Properties and Micro Structures of Laterite Steel

The Effect Holding Time Variation on the Process Of Heat Treatment Austempering on Mechanical Properties and Micro Structures of Laterite Steel

Effects of Martempering Heat Treatment on Corrosion Rate in 1.5Ni Laterite Steel

Laterite steel is commonly used for applications in the industrial worldwide. The behavior of this characteristics of laterite steel can be repaired in various ways, one of them by special heat treatment. This research aims to determine the value of corrosion rates, hardness, and transformation in microstructure that occur in laterite steel contain 1.564% Ni after heat treatment. Heat treatment carried out is austenizing at 950 ºC and then quenching water; oil and normalizing in the air. And also tempering temperature variations 100°C, 200°C, and 300°C. Tests carried out were CMS 100 corrosion test which is 3.5% NaCl solution media, hardness testing with Vickers scale, and metallographic testing using an optical microscope. The results obtained showed that a microstructure transformation in 1.564% Ni laterite steel after HT consisted of martensite, ferrite, pearlite, residual austenite, and bainite. The lowest value of corrosion rate obtained in the sample normalizing 300°C tempering air and the highest in raw material. Whereas the highest hardness value was obtained 459.7 HV in the non-tempered water quenching sample.

OPTIMIZATION OF MECHANICAL STRENGTH AND MICROSTRUCTURE ON AUSTEMPERING ZINC HEAT TREATMENT IN LATERITIC NICKEL STEELS

The development of lateritic steel is currently being discussed by various research institutions. It is not separated from the potential of laterite-based steel into national steel. This research using austempering heat treatment process with holding time variation for 30, 60, and 90 minutes with Zn (Zinc) element from melting ingot with 90% purity for cooling media. The characterization of laterite steel is done by hardness testing, impact resistance, microstructure, scanning electron microscopy, and energy dispersive spectroscopy. The results showed that the impact resistance value decreased 8.46%, which was initially 209 J to 191.3 J. Besides, the hardness value increased 36, 58% of which was originally 164 HV to 224 HV. Judging from its physical properties, the microstructure formed bainite ferrite perlite at holding time 90 minutes while the fracture is included into the ductile fracture because there are dimple holes showed dark and opaque

Study on Phases Development and Mechanical Properties in a Fe-Ni-Al Carbide Free Bainitic Steel Based on Lateritic Steel After Warm Rolling

The abundant reserve of lateritic ores in Indonesia is currently processed and studied to fulfil the national steel demand in several sectors, one of which is for railway application. The development of lateritic steel (Fe-Ni) as carbide free bainitic steel is carried out by adding Al to the Fe-Ni alloy. In this research, the effect of warm rolling and Al addition to the formation of carbide, phases development and mechanical properties was studied. The warm-rolled thermomechanical process (TMCP) was carried out by heating the material at 945°C for 20 minutes followed by second heating to 400°C, 450°C and 500°C with holding time for 30 minutes. The materials then warm rolled with 50% and 70% reductions using 20 tons capacity roller machine and then air cooled outside the furnace chamber. The microstructure of the as-rolled materials was characterized using optical microscope (OM) and scanning electron microscope (SEM), while the phases, the chemical distribution and the possibility of carbide formation were examine using X-Ray Diffraction (XRD) pattern and energy dispersive X-Ray spectroscopy (EDS). The mechanical properties of the material were observed using macro Rockwell hardness test. It was revealed that the addition of Al altered the phases of Fe-Ni lateritic steel significantly. Furthermore, Al addition gives positive effects to the Fe-Ni lateritic steel by increasing hardness. The reductions applied during warm rolling were observed to have effect on the growth of the grains in the Fe-Ni-Al lateritic steel.

Mechanical and microstructure properties of the Ni-Cr-Mo modified steel by heat treatment process

The development of Iron and steel is the fundamental essential needs for a construction. Indonesia should seek local raw materials for steelmaking production to cooperate with industrial markets. In this research, a new innovation in the manufacturing of bucket teeth components using laterite steel by optimizing the nickel alloy content reaches 1.5-3% and other alloys with special heat treatment process. The best results of optimization abrasion wear resistance and hardness properties on 1Cr1Mo steel with quenching oil treatment resulted in hardness of 43.60 HRC and had a good abrasive resistance of 0.16 gr/cm2 weight loss. In morphological analysis of microstructure showed that the grain boundaries become more flattened and sharpened into martensite phase transformation.

The effect of hot rolling on hardness properties and microstructure of laterite steel

Nickel containing pig iron (NCPI) is one of important materials for stainless steel and other iron-nickel alloys production. The natural source of NCPI in Indonesia is laterite ore. Large deposit of laterite ore has been found in South East Sulawesi. High grade laterite ore (saprolitic type of laterite ore) in this region has been used for ferronickel making, whereas low grade laterite ore (limonitic type of laterite ore) has not been processed, due to its too low nickel conten. However, laterite steel has not been widely reviewed as potential candidate for top national product comprehensively. Therefore, this study is aimed to know several aspects of its intrinsic properties by using hot roll process. A variety of thickness reduction on steel is used by rolling to know its mechanical properties especially hardness, followed by microstructure observation, and then compared with its as-cast. The result has shown that the highest hardness (282HRB) obtained in 31-35% reduction which is increased by 47,7% of as cast steel. Optical microscope images showed that ferrite phase and grain refinement which is caused an increasingon hardness. This study is expected as a reference for further research. The chemical composition of steel Laterite as more likely as HSLA steels with certain specialized alloys to obtain specific mechanical properties. Meanwhile the hardness of Laterite steel is possible for some products similar to AISI416 standard.

Microstructure and mechanical characteristics of hot forged lateritic steels

The current development of steel industry has constraints on the availability of raw materials, so we have developed local raw materials that are lateritic steels as a high potential for alternative manufacturing of steel. This research was conducted to understand the characteristics of lateritic steel through hot forging process by the mechanical and microstructure behaviour. The research methodology was chained by variety of preheating temperature of 800; 1000; 1200 °C and forging force from 0 until 1000 kilonewton. In case of hot forging values was obtained the impact and hardness properties also microstructure that compared with as-cast steels. The results of impact strength increased by 81.83% at the temperature of 1200 °C and the hardness increased by 4.99% at 1000 °C, for the microstructure analysis was produced the ferrite and pearlite phases with the fine grains. The chemical composition of steel is classified in low carbon steel included in lateritic steel it contains low alloy 1.78 Ni and 0.553 Cr %wt.

Characteristic of Mechanical and Morphological Properties of Heat Rolled Laterite Steel with Variety of Size Reduction

Indonesia has the most laterite ore reserves in the world. The element originated from the laterite ore is one of the materials in the steel industry. Despite its plentiful of reserves, laterite steel ore has not been used to its maximum potential. This research aims to overview reduction effect on mechanical properties of laterite steel as a result of heated rolling process with various reduction. The reduction variety used in this research were 30%, 40%, 50%, and 60%. Also, the temperature was 980oC. As a result of this research, the increment of reduction followed by the increment of hardness and firmness level of laterite steel. It is proofed by hardness and tensile test. Firmness of the material increased as the reduction increases. The most optimized mechanical properties obtained by 50% reduction, the hardness number was 280.03 HB, tensile strength 620 MPa, elongation 32%, yield 493.33 MPa. Micro structures which formed in this process are ferrite and pearlite phase with very fine pellet size and even pearlite distribution. Fracture types are brittle and ductile fracture with very fine pellet size.

Developing of Mechanical Properties for Reinforcing Bar Steel through Heat Treating with Various Cooling Media

In this study, mechanical properties development of reinforcing bar steel (rebar) has examined through heat treatment process. This rebar was made from low carbon lateritic steel with the small amount of alloying elements Cr,Mn and Ni. There were 4 rebar steel samples that consisted of rebar steel was applied hot rolled at 1200 °C at the beginning process in factory (sample A) and three others were conducted by quenching (sample B, C and D). The various of cooling media such as water (sample B), oil (sample C) and air (sample D) have applied to obtain different microstructure behavior and also mechanical properties. Initial heating was conducted to B,C and D rebar specimens at the austenitizing temperature (950 °C) for 1 h and followed by quenching. The experimental results showed that water quench exhibited of higher hardness level (50,26 HRC) for rebar steel but decreasing in toughness (34 Joule) and elongation (4%) than as cast because of martensite phase formed. Sample C showed that martensite and the small amount of retained austenite with hardness and tensile strength below the sample B, but elongation and energy absorbed were above. The lowest of hardness and tensile strength were obtained from sample D. It was appropriate with microstructuree formed as follows ferrite-pearlite phase and widmanstatten-bainite cluster. Nevertheless, sample D is suitable treatment for tensile strength and elongation requirements rebar standard, there are 558 Mpa and 26% respectively (min. 440 MPa and 20%).

THE INFLUENCE OF HEAT TREATMENT ON MICROSTRUCTURE AND MECHANICAL STRENGTH OF LATERITIC NICKEL STEEL

Indonesia has abundant resources of lateritic nickel ore and coal. However, this resource has not been considered as a main raw material in the Indonesian steel industry . Therefore, this study are aimed to investigate several aspects of lateritic nickel intrinsic propertiesand its potency through heat treatment process. Nickel laterite steels are usually used for bridge and building construction steel. Their properties can be improved in various ways, such as by conducting temper heat treatment. This research reported the influences of heat treatment on microstructure and mechanical strength in nickel laterite steel. Samples were austenitized at 900oC and subsquently tempered at 100 oC, 200 oC, 300 oC, 400 oC, 500 oC, and 600oC. Metallographic observation was conducted by using an optical microscope meanwhile mechanical strength were conducted by tensile test and surface hardness. The results showed evolution of mictrostructure in nickel laterite steel after heat treatment. The microstructure formed consisted of martensite temper. The presence of inclusion can affect brittle behavior of the lateritic nickel. The optimum tempering temperature was 200 oC. The result of Scanning Electron Microscope (SEM) fractography showed the dimple and intergranular fracture has caused a more ductile and mechanical behavior which is compatible with construction steels standard .