Materials Performance and Characterization Enhanced Hardenability and Tempering Resistance of AISI 4130 Steel by Ni Addition (original) (raw)
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Effect Of Quenching Media, Specimen Size And Shape On The Hardenability Of AISI 4140 Steel
2014
The purpose of this study is to investigate the influence of different quenching media, size and shape of the specimen on the hardened depth of AISI 4140 steel. The paper demonstrates how these parameters can affect the hardness from the surface to the core of the samples. This study represents the relationship between hardened depth and geometry. Findings reveal the fact that high hardening effect was obtained in water-quenched samples by the virtue of the martensitic structure and lower hardened depth achieved in the air-quenched samples. Significant improvement achieved by increasing the velocity of air when quenched by compressed air. It was also concluded that the hardness of the quenched samples at certain depths can be estimated on the basis of heat transfer equations.
QUENCH HARDENING AND MECHANICAL CHARACTERIZATION OF AISI 4140 STEEL
Transstellar Journals, 2019
AISI 4140 steel is the medium carbon low chromium steel used for a variety of structural applications. Generally this type of steel is available commercially in hot/cold rolled or as-cast conditions. This grade of steel has moderate strength and suitably responds almost to all type of heat treatments especially, hardening treatments. The present work is the effort in improving the mechanical properties of AISI 4140 steel by hardening treatment using different quenchants such as tap water, salt water (brine solution), ice water, castor oil, and coconut oil. Properties under consideration are wear, hardness and tensile strength. The change in property obtained by quenching is compared with that of as-bought steel. Ice water, coconut oil and castor oil quenched specimens show good wear resistance properties. Specimens quenched in ice water shows high hardness value (Rc 51.25). Castor oil quenched specimens show a highest percentage displacement (27.33%) and ultimate tensile strength of 1600.3N/mm2. Amongst the different quenchants used castor oil shows good result as a whole.
Effect of Tempering on Mechanical Properties of V-added AISI 4335 Steel
ISIJ international, 2010
NiCrMoV steels are known for their high hardenabil-ity, strength and toughness properties and are widely used for manufacturing of various armaments, turbine rotors and several heavy-duty components. The manufacturing processes, alloying technology, and heat ...
Materials & Design, 2012
This investigation is concerned to evaluate the effect of double quenching and tempering (DQT) with conventional quenching and tempering (CQT) heat treatment processes on microstructure and mechanical behavior of a commercially developed hot rolled AISI 4140 type steel. Comparison of microstructure and mechanical properties of DQT and CQT heat treated specimens have been established in details. Optical and scanning electron microscopies have been used to follow impurity concentration and microstructural changes, and their relation to the associated mechanical properties. The results indicate that the improvement of mechanical properties particularly impact toughness of DQT heat treated specimens is much higher than that of the CQT condition, and this observation is rationalized in terms of finer austenite grain size developed in the DQT condition providing much finer martensitic packets within the grains and a lower level of impurity concentration of sulfur (S) and phosphorus (P) near the prior austenite grain boundaries as well.
Materials Sciences and Applications, 2010
This research intends to find out the optimal mechanical properties of AISI 4130 steel welded by the GTAW process. Six test plates were joined by two types of filler wire with similar chemical composition to the base metal, and with lower carbon content and slightly higher alloy elements content compared to the first one. Test plates then exerted three different pre-heat and post-heat treatments on both groups. The three types of heat treatments were alternatively without pre-heat and post-heat, with pre-heat only, and finally with pre-heat and post-heat. Tensile, side bends and impact tests (for weld zone and HAZ) have been conducted. Results show that using low-carbon filler wire along with pre-and post-heat resulted in outstanding mechanical properties.
Tecnologia em Metalurgia, Materiais e Mineração, 2020
In this work the quenching and partitioning (Q&P) treatment is applied to AISI 9260 steel combining different quenching temperatures (QT), and partitioning times and temperatures in order to evaluate mechanical properties (e.g. ultimate tensile strength, elongatin, toughness, and their combination). AISI 9260 steel, besides having the advantage of a lower cost than most of the low alloy steels, can achieve high retained austenite (RA) fraction levels through the application of the Q&P treatment thanks to its few alloying elements, mainly silicon. The importance of RA lies in its ability to improve ductility and toughness; in this work, RA is determined via X-ray diffraction analysis (XRD) and the mechanical properties are assessed through conventional tensile test and, fracture toughness test (FT)-FT being seldom reported in several Q&P studies. The results of the present work suggest that the Q&P treatment applied to AISI 9260 steel could increase its industrial use by virtue of a good combination of strength, ductility and toughness.
Improving the Ductility of Locally Manufactured Steel Rods by Tempering
Journal Of The Ghana Science Association (GSA/Pub/Vol.5/2012/127)
Heat treatment was conducted to improve the ductility of locally manufactured mild steel rods (F e − 0.26 %C) obtained from Ferro-Fabrik, Tema, using tempering. Microstructural studies, hardness, impact and tensile tests were carried out on the mild steel rod samples before and after heat treatment. The samples were heated to 950 • C to austenitize them for 1 hour and rapidly quenched to room temperature in water to produce martensites. They were then re-heated to the tempering temperature of 500 • C for 1, 3 and 5 hours. Some of the martensitic samples were not tempered after quenching. The as-received samples (non-heat treated samples) had an average hardness value of 2290.5 ± 373.5 (Vickers Hardness 20) HV20. The martensitic samples had an average hardness value of 5477.0 ± 452.7 HV20. The samples tempered for 1 hour had an average hardness value of 2735.7 ± 577.6 HV20. The samples tempered for 3 hours had an average hardness value of 2470.2 ± 394.3 HV20 while the samples tempered for 5 hours had an average hardness value of 2198.6 ± 387.6 HV20. The as-received samples had an average impact energy value of 109.8 ± 6.8 J. The martensitic samples had an average impact energy value of 40.7 ± 5.0 J. The samples tempered for 1 hour had an average impact energy value of 114.3 ± 6.9 J. The samples tempered for 3 hours had an average impact value of 139.8 ± 2.3 J; while the samples tempered for 5 hours had an average impact value of 141.1 ± 3.9 J. From the tensile test the average percentage elongation of the as-received samples was 30.8 %. The martensitic samples had an average percentage elongation value of 17.5 %, whereas the samples tempered for 1, 3 and 5 hours had an average percentage elongation of 25 %, 30.0 % and 32.5 % respectively. The as-received and the martensitic samples had average percentage area reductions of 65.0 % and 42.5 % respectively. The samples tempered for 1, 3 and 5 hours at 500 • C had average percentage area reductions of 57.3 %, 64.0 % and 65.8 % respectively. The microstructure of the tempered samples revealed the formation of even distribution of ferrite and pearlite. The above results suggest that the ductility of locally manufactured mild steel rods may be improved by tempering.
International Journal of Materials Research, 2020
AISI 4340 is one of the most widely used steels in high-risk industries such as military, nuclear and aerospace. The strength of this steel is capable of increasing to 1 825 MPa with quench and temper heat treatment, but it results in low toughness, low impact properties and brittle-fracture especially at low temperatures. In this study, the intermediate quenching treatment was used to induce ferritic–martensitic dual-phase (∼50/50 ferrite/martensite) microstructure that led to an impact energy of 93.6 kJ m−2, which was 241% higher than that of quench and temper treatment. Moreover, mechanical tests revealed tensile strength and hardness of 911.5 MPa and 43 HRC, respectively. Also, fractographic analysis confirmed the occurrence of the desirable ductile fracture mechanism.
The mechanical properties of steel decide its applicability for a particular condition. Heat treatment processes are commonly used to enhance the required properties of steel. The material was machined to ASTM standards and then different tests like microstructure analysis, hardness test, impact test, etc. were carried out after the heat treatment processes. All the tests were carried out in the mechanical workshops and laboratories under the supervision of their respective faculty, at the MIT campus, Manipal. Heat treatment is necessary to obtain the required mechanical and physical properties for a material to make it suitable for fabrication. For this reason, the knowledge of heat treatment is necessary to suitably condition the material for the subsequent stages of manufacturing, or in the case of semi-finished components, to impart the desired mechanical and physical properties such as increased strength, toughness and wear resistance. Heat treatment is also resorted to relieve internal stresses and to soften hard metals in order to improve machinability. The outstanding advantage of steel as an engineering material is due to its versatility. Its properties can be controlled and changed at will by the heat treatment. Thus, if steel is to be formed into some intricate shape, it can be made very soft and ductile by the heat treatment, if, on the other hand, it is to resist water, it can be heat treated to a very hard, wear-resisting condition.
EFFECT OF HEAT TREATMENT AND MECHANICAL CHARACTERIZATION OF AISI 4140 STEEL
Transstellar journal, 2018
This work studies the outcome of heat treatment of AISI 4140 on wear, hardness, and tensile strength. The properties were compared after subject the specimen to annealing, normalizing, hardening and tempering. Amongst the methods used hardened specimen showed a hardness of RC45 and wear rate of near zero. Annealed specimen showed a Percentage Elongation of 15.56 and the tempered specimen had a tensile strength of 1109.4 N/mm2.