scholarly journals Effect of cooling rates after annealing on the microstructure and properties of 1000MPa grade automobile steel for cold forming

2021 ◽  
Author(s):  
Ruifeng Dong ◽  
Qingbo Zhao ◽  
Xiaohong Bi ◽  
Deng Xiangtao ◽  
Wentian Shen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cooling Rate ◽  
Testing Machine ◽  
Phase Region ◽  
Two Phase ◽  
Tensile Testing Machine ◽  
Cooling Rates ◽  
Cold Forming ◽  
Automobile Steel

Abstract The effects of different cooling rates ( 0.05℃/s, 0.1℃/s, and 0.2℃/s ) on the microstructure and mechanical properties of 1000 MPa grade automobile steel for cold forming after two-phase annealing were studied. The microstructure of the experimental steel was observed by SEM and TEM, and its mechanical properties were tested by a universal tensile testing machine. The results showed that by increasing the cooling rate of two-phase annealing, more massive retained austenite, more uniform and fine ferrite, better elongation and higher ultimate tensile strength of steel can be obtained, so as to obtain better production of tensile strength and total elongation ( product of tensile strength and elongation, PSE ). The final result shows that after the test steel is quenched at 800℃ + 10 minutes and annealed in the two-phase region at 690℃ + 10 minutes, the faster the cooling rate, the better the mechanical properties. The mechanical properties of the steel plate are the best when the cooling rate reaches 0.2℃/s, and PSE can reach 27.44 GPa·%.

Effect of Coarse-Grained Ring on Mechanical Properties and Cutting Performance of 2011 Aluminum Alloy Extruded Bar

2021 ◽  
Vol 1035 ◽  
pp. 114-118
Author(s):  
Chang Liang Shi ◽  
Yan Ping Niu ◽  
Yi Min Lin ◽  
Quan Hu ◽  
Xin Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Tensile Testing ◽  
High Speed ◽  
Testing Machine ◽  
Eutectic Phase ◽  
Cutting Performance ◽  
Coarse Grained ◽  
Tensile Testing Machine

The effects of coarse-grained ring on the mechanical properties and cutting performance of 2011 aluminum alloy extruded bars were studied by metallographic microscope, scanning electron microscope, tensile testing machine and high-speed lathe. The results show that the microstructure of aluminum alloy extruded bar was composed of α-Al phase, Al7Cu2Fe phase, CuAl2 phase and SnBi eutectic phase. There was a coarse-grained ring in the aluminum alloy extruded bar. The coarse-grained ring reduced the mechanical properties and cutting performance of the aluminum alloy extruded bar. The aluminum alloy extruded bar with a diameter of 30 mm had a coarse-grained ring depth of 9 mm and lower mechanical properties, whose the tensile strength was 287.9 MPa, the elongation was 17%, the cutting performance was poor and the chips were long. The aluminum alloy extruded bar with a diameter of 40 mm had a coarse-grained ring depth of 1 mm, higher mechanical properties and better cutting performance, whose the tensile strength was 394.5 MPa, the elongation was 23.5%, the chips were fine and uniform.

scholarly journals Effect of Heat Treatment on the Mechanical Properties of Two-Phase Titanium Alloy Ti6al7nb/ Wpływ Obróbki Cieplnej Na Własności Mechaniczne Dwufazowego Stopu Tytanu Ti6al7nb

2014 ◽  
Vol 59 (4) ◽  
pp. 1713-1716 ◽  
Author(s):  
R. Dąbrowski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Titanium Alloy ◽  
Yield Strength ◽  
Cooling Rate ◽  
Strength Properties ◽  
Two Phase ◽  
Impact Tests ◽  
Alloy Heat

Abstract Mechanical properties of the two-phase titanium alloy Ti6Al7Nb, after the heat treatment based on soaking this alloy in the α + β range, cooling in water or oil and ageing at two selected temperatures, were determined in the hereby paper. The alloy mechanical properties were determined in tensile and impact tests, supported by the fractographic analysis of fractures. In addition, its hardness was measured and the analysis of changes occurring in the microstructure was performed for all variants of the alloy heat treatment. Regardless of the applied cooling rate of the alloy, from a temperature of 970°C followed by ageing at 450 and 650°C, none essential changes were noticed in its microstructure. It was shown that applying less intensive cooling medium (oil) instead of water (before tempering) decreases strength properties indicators, i.e. tensile strength and yield strength as well as hardness (only slightly). The decrease of the above mentioned indicators is accompanied by an increase of an elongation and impacts strength. Fractures of tensile and impact tests are of a ductile character regardless of the applied heat treatment.

Heat Treatment, Mechanical Properties and Microstructure of T-Joint Steel Arc Welded

2018 ◽  
Vol 876 ◽  
pp. 36-40
Author(s):  
Yustiasih Purwaningrum ◽  
Dwi Darmawan ◽  
Panji Lukman Tirta Kusuma
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Weld Metal ◽  
Testing Machine ◽  
Optical Microscope ◽  
Heat Treatments ◽  
Tensile Testing Machine ◽  
Weld Metals ◽  
Quenching Process

Heat treatment of T-Joint’s steel arc welded are performed are investigated in this research. The heat treatment process that used were annealing and quenching. The microstructure was investigated by optical microscope. The mechanical behavior of the samples was investigated using universal tensile testing machine for tensile test and Microvickers hardness method for hardness testing. The microstructure of welding zone of welding metals with various heat treatments is grain boundary ferrite, Widmanstatten ferrite and acicular ferrite. The weld metal with quenching treatment has a highest tensile strength with tensile strength 197.97 Mpa. The quenching process increases the tensile strength by 49.58 %. The distortion value in weld metal without heat treatment, quenching and annealing is 0.11mm; 0.04 mm and 0.08 mm respectively. The hardness number of weld metals with quenching process have a highest number base metal, HAZ and weld metals. Results showed that the mechanical properties of T-joints steel arc welded can be improved by various heat treatments.

The Effect of Temperature on the Tensile Properties of Steel 0Cr18Ni9

2010 ◽  
Vol 654-656 ◽  
pp. 194-197
Author(s):  
Wei Fen Li ◽  
Wei Niu ◽  
Zhi Ming Hao ◽  
Ming Hai Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Tensile Properties ◽  
Tensile Testing ◽  
Testing Machine ◽  
Effect Of Temperature ◽  
Tensile Testing Machine ◽  
Increasing Temperature

Experiments of tensile mechanical properties of steel 0Cr18Ni9 are done on the MTS 810 tensile testing machine, and the temperature range is from 20°C to 1200°C. The stress vs. strain curves are obtained. Results show that the elastic modulus, yield stress and tensile strength decrease with increasing temperature .Based on the experiment results, the functions of the elastic modulus, yield strength and tensile strength versus temperature are represented by polynomial.

Effect of Cooling Rate on the Microstructure and Mechanical Properties of Sn-0.7wt.%Cu Solder Alloy

2016 ◽  
Vol 675-676 ◽  
pp. 513-516 ◽  
Author(s):  
Phairote Sungkhaphaitoon ◽  
Thawatchai Plookphol
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Cooling Rate ◽  
Solder Alloy ◽  
Solder Alloys ◽  
Cooling Systems ◽  
Cooling Rates ◽  
Microstructure And Mechanical Properties ◽  
Two Phases

The dependence of microstructure and mechanical properties of Sn-0.7wt.%Cu solder alloys on different cooling rates were investigated. Two cooling rates were employed during solidification: 0.04 °C/s (mold-cooled system) and 1.66 °C/s (water-cooled system). The results showed that the ultimate tensile strength of Sn-0.7wt.%Cu solder alloy increased but the elongation decreased when water-cooled system was used. The microstructure of Sn-0.7wt.%Cu solder alloys solidified by both cooling systems exhibited two phases of Sn-rich and Cu6Sn5 intermetallic compounds (IMCs). However, finer grains were observed in the water-cooled specimens.

Effect of laser inclination angle on mechanical properties of Hastelloy X processed by selective laser melting

2021 ◽  
Vol 63 (1) ◽  
pp. 10-16
Author(s):  
Zong Xuewen ◽  
Zhang Jian ◽  
Fu Hanguang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Temperature Field ◽  
Yield Strength ◽  
Cooling Rate ◽  
Selective Laser Melting ◽  
Inclination Angle ◽  
Laser Melting ◽  
Cooling Rates ◽  
Hastelloy X

Abstract Selective laser melting at various laser inclination angles was used to prepare Hastelloy X alloy specimens. The morphology, fracture, tensile strength, stress, and strain of Hastelloy X alloy specimens were studied using optical microscopy, scanning electron microscopy, and a tensile tester. The temperature field of the manufacturing process was analyzed based on finite element analysis, and the internal relationship between the temperature field and the process was constructed in terms of cooling speed. The results show that the temperature field is a dynamic process with a high cooling rate; the average cooling rate reaches 3.23 × 106 °C × s−1. The greater the inclination angle, the greater the thermal gradient, resulting in higher cooling rates. Due to the cross-influence of grain refinement at high cooling rates and residual stress, the tensile strength and yield strength of Hastelloy X alloy showed first increasing and then decreasing trends with respect to inclination angle. However, at an inclination angle of 30°, the voids and crack defects of Hastelloy X alloy fractures were reduced, and the tensile strength and yield strength reached 881.38 and 701.60 MPa, respectively. At this angle, the mechanical properties were excellent and met the requirements of the aviation industry.

scholarly journals Preparation of Miscible PVA/PEG Blends and Effect of Graphene Concentration on Thermal, Crystallization, Morphological, and Mechanical Properties of PVA/PEG (10 wt%) Blend

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Fahad H. Falqi ◽  
Osamah A. Bin-Dahman ◽  
M. Hussain ◽  
Mamdouh A. Al-Harthi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Testing Machine ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
Tensile Testing Machine ◽  
Elongation At Break ◽  
Casting Technique ◽  
Dsc Studies

Water-soluble polymers such as poly(vinyl alcohol) (PVA) and poly(ethylene glycol) (PEG) and their nanocomposites with graphene were prepared by using a solution mixing and casting technique. The effect of different PEG loadings was investigated to determine the optimum blend ratio. The films were characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA) methods. Also, the mechanical properties including tensile strength and elongation at break were measured using a universal tensile testing machine. FTIR results confirmed the formation of the H-bond between PEG and PVA. DSC studies revealed that PEG has a significant plasticization effect on PVA as seen by the drop in the glass transition temperature (Tg). The blend with 10 wt% PEG loading was found to be the optimum blend because of good compatibility as shown by FTIR and SEM results and improved thermal properties. PVA/PEG (10%) nanocomposites were prepared using graphene as a nanofiller. It was found that the elongation at break increased by 62% from 147% for the PVA/PEG (10%) blend to 209% for the nanocomposite with graphene loading of 0.2 wt%. The experimental values of tensile strength were compared using the predictive model of Nicolais and Narkis.

scholarly journals Experimental Investigations on the Induced Anisotropy of Mechanical Properties in Polycarbonate Films

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Andrea Wibbeke ◽  
Volker Schöeppner ◽  
Rolf Mahnken
Keyword(s):  
Mechanical Properties ◽  
Testing Machine ◽  
Polymer Materials ◽  
Major Influence ◽  
Experimental Investigations ◽  
Induced Anisotropy ◽  
Tensile Testing Machine ◽  
Cold Forming ◽  
Two Phases ◽  
Anisotropy Of Mechanical Properties

The prime aim of this paper is to investigate, with the help of experiments, the induced anisotropy of mechanical properties in polycarbonate films. It is known that a molecular orientation in polymer materials occurs through cold-forming. In this study, cold forming is performed at room temperature on a tensile testing machine. The polycarbonate films are examined in two phases. In the first phase, the specimen is loaded, while the prestrain is varied, and in the second, it is loaded, while the material direction is varied. The main findings are that the prestrain has virtually no influence on the anisotropy and that the material direction does exert a major influence. Furthermore, this paper summarizes comparisons of anisotropic characteristic data, maximum stresses, elasticity moduli and failure strain.

Studies on Nanostructured Polyurethane/Clay Interpenetrating Polymer Networks

2005 ◽  
Vol 475-479 ◽  
pp. 1001-1004
Author(s):  
Ninglin Zhou ◽  
Xiao Xian Xia ◽  
Li Li ◽  
Shao Hua Wei ◽  
Jian Shen
Keyword(s):  
Mechanical Properties ◽  
Polymer Networks ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Interpenetrating Polymer Networks ◽  
Absorption Properties ◽  
Tensile Testing Machine ◽  
Swelling Agent ◽  
Silicate Layers ◽  
Polyurethane Matrix

A novel exfoliated polyurethane (PU)/clay Interpenetrating Polymer Networks (IPNs) nanocomposite has been synthesized with polyurethane and organoclay. MTPAC is used as swelling agent to treat Na-montmorillonite for forming organoclay. The results indicate that there is very good compatibility between organoclay and PU. Nanoscale silicate dispersion was analyzed by XRD. The mechanical properties of the nanocomposites have been measured by tensile testing machine. The nanocomposites show obviously improved physical and mechanical properties when compared with the pure polymer. Additionally, PU /MTPAC- clay shows lower water absorption properties than pure PU do. In addition, the reinforcing and intercalating mechanism of silicate layers in polyurethane matrix are discussed.

scholarly journals Styrene–Acrylic Emulsion with “Transition Layer” for Damping Coating: Synthesis and Characterization

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1406
Author(s):  
Daoyuan Chen ◽  
Mingjin Ding ◽  
Zhixiong Huang ◽  
Yanbing Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Transition Layer ◽  
Testing Machine ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Latex Film ◽  
Seeded Emulsion Polymerization ◽  
Acrylic Emulsion ◽  
Dynamic Mechanical

In order to study the dynamic mechanical properties of styrene–acrylic latex with a core/shell structure, a variety of latexes were synthesized by semi-continuous seeded emulsion polymerization based on “particle design” with the same material. The latexes were characterized by rotary viscosimeter, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), dynamic mechanical analysis (DMA), and universal testing machine. The effects of difference at the glass transition temperature (Tg) of core and shell and the introduction of the “transition layer” on the damping and mechanical properties of latex film were studied. The results indicate that as the Tg of core and shell gets closer, the better the compatibility of core and shell, from phase separation to phase continuity. Furthermore, the introduction of the “transition layer” can effectively improve the tensile strength and tan δ (max) of the latex film. The tensile strength and maximum loss factor (f = 1 Hz) of latex with the “transition layer” increased by 36.73% and 29.11% respectively compared with the latex without the “transition layer”. This work provides a reference for the design of emulsion for damping coating.

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