Effect of Austenite on Drawing Limit of Ferrite-Austenite Dual Phase Wire

2010 ◽  
Vol 654-656 ◽  
pp. 78-81 ◽  
Author(s):  
Seung Hyun Lee ◽  
Hu Chul Lee
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Mechanical Stability ◽  
Volume Fraction ◽  
Void Nucleation ◽  
True Strain ◽  
Nucleation Site ◽  
Dual Phase ◽  
Number Density ◽  
Intermediate Heat Treatment

The drawability of ferrite-austenite dual phase wires decreased with increasing volume fraction and decreasing mechanical stability of austenite. The interface of the martensite and ferrite was identified as the void nucleation site and the number density of voids increased with increasing austenite volume fraction. The plastic incompatibility at the interface was assumed to be the main reason for void nucleation. The ferrite-austenite dual phase steels could be drawn to a maximum true strain of 8.0 without intermediate heat treatment. The tensile strength of the drawn wires increased with increasing volume fraction of austenite or, in other words, with increasing volume fraction of transformed martensite.

scholarly journals Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Energy Impact ◽  
Treatment Conditions ◽  
Mold Casting ◽  
Grade 3 ◽  
Good Agreement

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

Micro Palm and Kenaf Fibers Reinforced PLA Composite: Effect of Volume Fraction on Tensile Strength

2011 ◽  
Vol 145 ◽  
pp. 1-5 ◽  
Author(s):  
K.W. Neoh ◽  
Kim Yeow Tshai ◽  
P.S. Khiew ◽  
Chin Hua Chia
Keyword(s):  
Tensile Strength ◽  
Mechanical Stability ◽  
Volume Fraction ◽  
Environmental Concern ◽  
Raw Materials ◽  
Kenaf Fiber ◽  
Composite Effect ◽  
Fiber Loading ◽  
Biodegradable Composite ◽  
Kenaf Fibers

Extensive environmental concern associated with the disposal of solid plastic wastes has stirred tremendous interest in the production and use of sustainable biodegradable polymers. Among the vast variety of available materials, Polylactic Acid (PLA) standout as the most commercially viable mass produced resin to date. However, its low thermal and mechanical stability, excessive brittleness, and relatively higher cost have led to numerous research efforts in producing biodegradable polymer composite filled with natural organic fibers. This paper describes the preparation and the mechanical characteristics of a compression molded biodegradable composite made entirely of renewable raw materials. The composites were reinforced with pulverized palm, kenaf and alkali (1M NaOH:fiber in ratio 2:1) treated kenaf fibers, at a fiber mass proportion of 20 to 60% blended PLA and processed in a custom-built compression mold. SEM microscan revealed that the kenaf fiber has a mean diameter of 40μm, length 1236.6μm, and aspect ratio of 31 while the measured values for palm fiber was 58.7μm, 1041.2μm, and 17.7, respectively. All resulting composites showed significant enhancement in tensile strength. At 20, 40 and 60% fiber loading, the palm/PLA composite recorded tensile strength increment of 46.9, 47.8 and 36.6%, respectively. For the kenaf/PLA composite, greatest improvement was achieved at 40% fiber loading with alkali treated kenaf, with approximately 54% higher than the neat PLA while only 12.6% was recorded for the non-treated kenaf/PLA composite, signifying that the surface modification greatly improved fiber-matrix adhesion. SEM observations on the fracture surface showed similar findings. Compared to commercially available palm/Polypropylene (palm/PP) composite at 50% fiber loading, our measured tensile strength for the PLA composite loaded with 40% alkali treated kenaf fiber was still about 20% lower. Further enhancement in the mechanical characteristic of the kenaf/PLA composite is required to push for its wider utilization in the polymer industry.

Influence of Volume Fraction of Bainite on Mechanical Properties of X80 Pipeline Steel with Excellent Deformability

2011 ◽  
Vol 695 ◽  
pp. 271-274
Author(s):  
Xiao Yong Zhang ◽  
Hui Lin Gao ◽  
Xue Qin Zhang ◽  
Yan Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Volume Fraction ◽  
Pipeline Steel ◽  
Dual Phase ◽  
Absorption Energy ◽  
Impact Absorption Energy ◽  
Impact Absorption ◽  
Work Hardening Exponent

The pipeline steel with excellent deformability with ferrite and bainite dual-phase microstructure are obtained by inter-critically accelerating cooling method, aiming to get good deformation capability of avoiding failure from the geological disasters such as landslides and earthquake. The influence of volume fraction of bainite on the mechanical properties of dual-phase pipeline steels was investigated by means of microscopic analysis method and mechanical properties testing. The results indicated that both yield strength and ultimate tensile strength of the steels increase almost linearly with the increasing volume fraction of bainite, while ductility, work hardening exponent and impact absorption energy decrease. When the volume fraction of bainite is about 50%, the yield strength, the yield strength/tensile strength ratio (Y/T), work hardening exponent, uniform elongation and impact absorption energy of X80 pipeline steels with excellent deformability is 665MPa, 0.8, 0.12, 8% and 245J respectively.

scholarly journals Prediction of Strength and Ductility in Partially Recrystallized CoCrFeNiTi0.2 High-Entropy Alloy

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 389 ◽  
Author(s):  
Hanwen Zhang ◽  
Peizhi Liu ◽  
Jinxiong Hou ◽  
Junwei Qiao ◽  
Yucheng Wu
Keyword(s):  
Tensile Strength ◽  
Single Phase ◽  
Volume Fraction ◽  
Tensile Elongation ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Number Density ◽  
High Entropy ◽  
Average Size ◽  
Strength And Ductility

The mechanical behavior of a partially recrystallized fcc-CoCrFeNiTi0.2 high entropy alloys (HEA) is investigated. Temporal evolutions of the morphology, size, and volume fraction of the nanoscaled L12-(Ni,Co)3Ti precipitates at 800 °C with various aging time were quantitatively evaluated. The ultimate tensile strength can be greatly improved to ~1200 MPa, accompanied with a tensile elongation of ~20% after precipitation. The temporal exponents for the average size and number density of precipitates reasonably conform the predictions by the PV model. A composite model was proposed to describe the plastic strain of the current HEA. As a consequence, the tensile strength and tensile elongation are well predicted, which is in accord with the experimental results. The present experiment provides a theoretical reference for the strengthening of partially recrystallized single-phase HEAs in the future.

Ductile Fracture Behavior of Bainite-MA Dual Phase Steels

2014 ◽  
Author(s):  
Junji Shimamura ◽  
Kyono Yasuda ◽  
Nobuyuki Ishikawa ◽  
Shigeru Endo
Keyword(s):  
Ductile Fracture ◽  
Fracture Behavior ◽  
Volume Fraction ◽  
Void Nucleation ◽  
Ground Movement ◽  
Dual Phase ◽  
Dual Phase Steels ◽  
Boundary Area ◽  
Strain Capacity ◽  
Shelf Region

In order to achieve safety and reliability of the pipeline installed in seismic region, it is quite important to apply the high-strength linepipes with sufficient strain capacity against buckling and weld fracture by the seismic ground movement. Dual-phase microstructure control is an essential measure for improving strain capacity of linepipe steels. Ferrite-bainite or bainite-MA microstructures are practically applied to the linepipes for the strain-based design to achieve higher deformability which has low Y/T (Yield/Tensile strength) ratio and high uniform elongation even after pipe coating. On the other hand, dual-phase steels tend to show lower Charpy energy in the upper shelf region than single-phase steel. It is considered that void nucleation and growth is enhanced in the dual-phase steels due to the strain concentration at the boundary between two different phases, resulting in early cracking in the specimen that leads to lower Charpy energy. The Charpy energy of the bainite-MA dual-phase steels was strongly affected by the volume fraction and size of MA. In the case of Bainite-MA steels with fewer volume fraction of MA and smaller size of MA, the sample showed higher Charpy energy. Ductile fracture behavior was investigated through several kinds of Charpy impact tests in order to clarify the effect of these microstructure differences on the Charpy energy in the upper shelf region. From the SEM observation, it was found that void nucleation was enhanced in the sample with higher volume fraction of MA and larger size of MA. It is considered that the increase of boundary area that works as void nucleation site affected these results. Experimental results were mainly discussed in this paper.

scholarly journals Correlations and Scalability of Mechanical Properties on the Micro, Meso and Macro Scale of Precipitation-Hardenable Aluminium Alloy EN AW-6082

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 608
Author(s):  
Anastasiya Toenjes ◽  
Heike Sonnenberg ◽  
Axel von Hehl
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminium Alloy ◽  
Aluminium Alloys ◽  
Volume Fraction ◽  
Solution Annealing ◽  
Macro Scale ◽  
Testing Cost ◽  
Physical Correlations

The mechanical properties of heat-treatable aluminium alloys are improved and adjusted by three different heat treatment steps, which include solution annealing, quenching, and aging. Due to metal-physical correlations, variations in heat treatment temperatures and times lead to different microstructural conditions with differences in the size and number of phases and their volume fraction in the microstructure. In this work, the investigations of the correlation between microhardness measurements on micro samples and the conventional mechanical properties (hardness, yield strength and tensile strength) of macro samples and the comparability of the different heat treatment states of micro and macro samples made of a hardenable aluminium alloy EN AW-6082 will be discussed. Using the correlations between the mechanical properties of micro samples and macro samples, the size of the samples and, thus, the testing cost and effort can be reduced.

The Influence of Quenching Temperature on the Mechanical Properties of a Dual-Phase Steel with 0.094% C and 0.53% Mn

2015 ◽  
Vol 808 ◽  
pp. 28-33 ◽  
Author(s):  
Constantin Dulucheanu ◽  
Nicolai Bancescu ◽  
Traian Severin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Dual Phase Steel ◽  
Volume Fraction ◽  
Total Elongation ◽  
Metallographic Analysis ◽  
Dual Phase ◽  
Quenching Temperature ◽  
Offset Yield Strength ◽  
Martensite Structure

In this article, the authors have analysed the influence of quenching temperature (TQ) on the mechanical properties of a dual-phase steel with 0.094 % C and 0.53% Mn. In order to obtain a ferrite-martensite structure, specimens of this material have been the subjected to intercritical quenching that consisted of heating at 750, 770, 790, 810 and 830 °C, maintaining for 30 minutes and cooling in water. These specimens have then been subjected to metallographic analysis and tensile test in order to determine the volume fraction of martensite (VM) in the structure, ultimate tensile strength (Rm), the 0.2% offset yield strength (Rp0.2), the total elongation (A5) and the Rp0.2/Rm ratio.

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