Influence of Thermal Ageing on Microstructure and Tensile Properties of P92 Steel

2018 ◽  
Vol 37 (5) ◽  
pp. 425-435 ◽  
Author(s):  
T. Sakthivel ◽  
S. Panneer Selvi ◽  
P. Parameswaran ◽  
K. Laha
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Thermal Exposure ◽  
Laves Phase ◽  
Area Fraction ◽  
Aged Condition ◽  
Lower Yield Stress ◽  
P92 Steel ◽  
Phase Precipitate ◽  
The Matrix

AbstractMicrostructure and tensile properties of P92 steel in the normalized and tempered, and thermal aged at 923 K for 5000 h and 10,000 h conditions have been investigated. Laves phase precipitate was observed in the thermal-aged steels. The size of Laves phase precipitate increased with increase in thermal exposure. This was also confirmed from the observation that the area fraction of Laves phase precipitate was higher in the 5000 h aged condition which decreased with further increase in thermal exposure. On the other hand, the size and area fraction of M23C6 precipitate were found increased in the 5000 h aged steel, further continued to enhanced precipitation of fine M23C6 in the 10,000 h aged steel. This resulted in significant increase in area fraction and comparable size with the steel aged for 5000 h. Hardness of the steel was decreased with increase in the duration of ageing. Thermal-aged steels exhibited lower yield stress, ultimate tensile strength and relatively higher ductility in comparison with steel in the normalized and tempered condition. The increase in lath width and recovery of dislocation structure under thermal-aged condition resulted in lower tensile strength and hardness. An extensive Laves phase formation and coarsening by loss of tungsten in the matrix led to decrease in the tensile strength predominantly in the 5000 h aged steel. The tensile strength of 10,000 h aged steel was comparable with that of 5000 h aged steel due to enhanced precipitation of fine M23C6 in the steel due to enhanced mobility of carbon in the absence of tungsten in the matrix.

Effect of TMT Process on the Strength and Precipitation Behavior of an 11Cr-0.3Mo-1.6W Steel during Long Term Aging

2007 ◽  
Vol 345-346 ◽  
pp. 1565-1568
Author(s):  
Sang Min Song ◽  
Woo Sang Jung ◽  
Suk Woo Hong ◽  
Deuck Seung Bae ◽  
Soon Hyo Chung ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Mechanical Treatment ◽  
Laves Phase ◽  
Precipitation Behavior ◽  
Aged Condition ◽  
Nucleation Sites ◽  
Conventional Heat Treatment ◽  
Thermo Mechanical Treatment ◽  
The Difference

The effect of thermo-mechanical treatment (TMT) process on the strength and precipitation behavior of an 11%Cr-0.3Mo-1.6W steel during long term aging was investigated. The major precipitates in as-tempered specimen were identified as M23C6 (M=Fe,Cr) and MX (M=Ta,V;X=C,N). The M23C6 precipitate in TMT sample was more finely distributed due to the increased heterogeneous nucleation sites at dislocations. The tensile strength of TMT sample is higher than that of the conventional heat treatment (CHT) sample in as-tempered condition. However, Laves phase starts to precipitate additionally in the aged condition. The growth rate of Laves phase in TMT sample is much faster than that in CHT sample. Therefore, the difference in tensile strength between CHT and TMT sample decreases as the aging time increases.

Microstructure and Tensile Properties of Mg-4Zn-2Sn-2Al Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 398-403 ◽  
Author(s):  
Dong Qing Zhao ◽  
Xu Guang Dong ◽  
Xin En Zhang ◽  
An Jiang Gao ◽  
Ji Xue Zhou ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Tensile Properties ◽  
Aging Process ◽  
Supersaturated Solid Solution ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Solution Treated ◽  
The Matrix ◽  
Alloy Increase

The microstructures and tensile properties of as-cast, solution-treated and aged Mg-4Zn-2Sn-2Al (wt.%) alloy have been investigated. The microstructure of the as-cast alloy consists of α-Mg, Mg2Sn and Mg32(Al,Zn)49 phases. The yield tensile strength and the ultimate tensile strength of the as-cast alloy are 87.7 MPa and 241.3 MPa, respectively, and the elongation reaches to 18.8% showing excellent ductility. After solution treatment, all of the Mg32(Al,Zn)49 phase and the majority of Mg2Sn particles have dissolved into the matrix. During aging process, Mg2Sn phase precipitates from the α-Mg supersaturated solid solution. With the precipitation strengthening of Mg2Sn phase, the yield tensile strength and the ultimate tensile strength of the alloy increase to 112.5 MPa and 280.4 MPa, respectively, while, the elongation decreases to 12%.

Microstructure and Tensile Properties of a Mg-5Sn-4Al Alloy

2011 ◽  
Vol 287-290 ◽  
pp. 343-347 ◽  
Author(s):  
Shou Qiu Tang ◽  
Ji Xue Zhou ◽  
Yuan Sheng Yang ◽  
Chang Wen Tian
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Aging Process ◽  
Room Temperature ◽  
Fine Particles ◽  
Solution Treatment ◽  
Cast Sample ◽  
Solution Treated ◽  
The Matrix ◽  
Alloy Increase

The microstructure and tensile properties at room temperature of as-cast, solution-treated and aged samples of a Mg-5Sn-4Al (wt%) alloy are investigated. The microstructure of the as-cast sample consists of a-Mg primary, Mg2Sn and Mg17Al12divorced eutectic, secondary precipitations Mg17Al12and Mg2Sn. After solution treatment, all the Mg17Al12particles and the majority of Mg2Sn phases are dissolved into the matrix and the tensile strength and the elongation of the alloy increase obviously. During aging process many fine particles of Mg2Sn precipitate which result in the improvement of the yield strength.

Poly(∊-Caprolactone) Composites Reinforced with Short Abaca Fibres

2003 ◽  
Vol 11 (5) ◽  
pp. 359-367 ◽  
Author(s):  
Mitsuhiro Shibata ◽  
Ryutoku Yosomiya ◽  
Noritaka Ohta ◽  
Atsushi Sakamoto ◽  
Hiroyuku Takeishi
Keyword(s):  
Tensile Strength ◽  
Acetic Anhydride ◽  
Tensile Properties ◽  
Weight Fraction ◽  
Natural Fibre ◽  
Fibre Content ◽  
Melt Mixing ◽  
The Matrix ◽  
Poly Caprolactone ◽  
Butyric Anhydride

The tensile properties of poly( ∊-caprolactone) (PCL) composites reinforced with short abaca fibres (length ca. 5 mm) prepared by melt mixing and subsequent injection molding were investigated and compared with PCL composites reinforced with glass fibres (GF). The influence of fibre content and surface esterification of the natural fibre on the tensile properties was evaluated. The tensile strength and moduli of all the PCL/abaca composites increased with increasing fibre content. All the PCL/abaca composites had a higher tensile strength than the PCL/GF composites when the fibre weight fraction was the same. The tensile strength of the PCL/abaca composites was improved by surface esterification of the abaca with acetic anhydride or butyric anhydride in the presence of pyridine, because of the increase in the interfacial adhesiveness between the matrix polyester and the esterificated fibre, as is obvious from the SEM photographs.

Effects of Thermal Cycling and Freezing after Water Absorption on Tensile Properties of Green Composites

2010 ◽  
Vol 150-151 ◽  
pp. 961-964
Author(s):  
Hyojin Kim ◽  
Masataka Sakiyama ◽  
Kenichi Takemura
Keyword(s):  
Tensile Strength ◽  
Thermal Cycling ◽  
Water Absorption ◽  
Tensile Properties ◽  
Thermal Fatigue ◽  
Room Temperature ◽  
Freezing Temperature ◽  
Freezing Process ◽  
Green Composites ◽  
The Matrix

The effects of thermal cycling and freezing after water absorption on tensile properties of green composites were examined. Jute fiber and matrix were used as the reinforcement and the matrix. The thermal fatigue was conducted as a fatigue test. Heating and freezing process are performed alternately for 0.5h, 1h and 24h during 10 cycles, heating and freezing temperature were 60 and -20 . In a freezing after water absorption, the damage by an expansion of water was examined. The freezing after the water absorption during 1-5 days was performed in a day under the environment of -20 . In thermal cycling, tensile strength and modulus were significantly decreased as the time passes. In 24h-treated test, the decrease rates of tensile strength and modulus were about 50 % compared with that of room temperature. In freezing after water absorption, tensile strength and modulus were decrease compared with that of the room temperature.

Effect of Fibre Size on the Tensile Properties of Oil Palm Empty Fruit Bunch Fibre Composites

2012 ◽  
Vol 576 ◽  
pp. 280-283 ◽  
Author(s):  
Noorrul Wahida Abdul Razak ◽  
Anizah Kalam
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Oil Palm ◽  
Matrix Material ◽  
Tensile Modulus ◽  
Empty Fruit Bunch ◽  
Fibre Size ◽  
Fibre Composites ◽  
The Matrix ◽  
Pp Composites

The principal aim of this project was to achieve a better understanding of the various parameters that contribute to the tensile properties. These parameters were manipulated in order to improve and produced PPnanoclay/ Polypropylene (PP) reinforced oil palm empty fruit bunch composite material (OPEFB). OPEFB fibre was treated with sodium hydroxide (NaOH) in order to improve the tensile properties of the composites. Thus, in this study the oil palm empty fruit bunch fibres were used as a filler and PPnanoclay/ PP composite as the matrix material. Tensile test was used to assess the effect on the tensile strength and tensile modulus of OPEFB/PPnanoclay/PP composites. Morphologies of the composites were examined using a scanning electron microscope (SEM). The average tensile properties obtained were tensile strength 22 MPa at 180 µm and Young’s modulus 2120 MPa at 355 µm treated.

scholarly journals Study on the Macro and Micromechanics Tensile Strength Properties of Orange Tree Pruning Fiber as Sustainable Reinforcement on Bio-Polyethylene Compared to Oil-Derived Polymers and Its Composites

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2206
Author(s):  
Francesc X Espinach ◽  
Eduardo Espinosa ◽  
Rafel Reixach ◽  
Alejandro Rodríguez ◽  
Pere Mutjé ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Value Chain ◽  
Strength Properties ◽  
Wood Fibers ◽  
Huge Amount ◽  
Polyethylene Matrix ◽  
Orange Tree ◽  
The Matrix ◽  
Tree Pruning

Agroforestry creates value but also a huge amount of waste outside its value chain. Tree pruning is an example of such a low value waste, that is typically discarded or incinerated in the fields or used to recover energy. Nonetheless, tree prunings are rich in wood fibers that can be used as polymer reinforcement. Although there are some bio-based polymers, the majority of industries use oil-based ones. The election of the materials is usually based on a ratio between properties and cost. Bio-based polymers are more expensive than oil-based ones. This work shows how a bio-polyethylene matrix can be reinforced with fibers from orange tree prunings to obtain materials with notable tensile properties. These bio-based materials can show a balanced cost due to the use of a cheap reinforcement with an expensive matrix. The matrix used showed a tensile strength of 18.65 MPa, which reached 42.54 MPa after the addition of 50 wt.% of reinforcement. The obtained values allow the use of the studied composite to replace polypropylene and some of its composites under tensile loads.

Tensile Properties of 15wt. %TiB2/7055 Composite Fabricated by In Situ Method

2013 ◽  
Vol 842 ◽  
pp. 165-169 ◽  
Author(s):  
Dong Chen ◽  
Cong Zou ◽  
Yi Jie Zhang ◽  
Nai Heng Ma ◽  
Hao Wei Wang
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
Tensile Properties ◽  
Matrix Alloy ◽  
In Situ Method ◽  
The Matrix ◽  
7055 Aluminum Alloy

7055 aluminum alloy reinforced with 15wt. % TiB2 particulates was synthesized by in situ method, the microstructure and tensile properties were investigated. There are a few particulate clusters in the matrix. The elastic modulus and hardness of the composite are higher than that of the matrix alloy, but the yield strength and ultimate tensile strength decrease. The decrease of strength is attributed to the presence of TiB2 particulate cluster and residual reaction slag.

Combination of silk fabric and natural rubber for the development of green composites: Influence of curing on mechanical and thermal properties

2021 ◽  
pp. 096739112110491
Author(s):  
Thanuj Kumar M ◽  
Sanga Shetty S G ◽  
Ekwipoo Kalkornsurapranee ◽  
Ladawan Songtipya ◽  
Yeampon Nakaramontri ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Physical Properties ◽  
Tensile Properties ◽  
Mechanical And Thermal Properties ◽  
Relaxation Techniques ◽  
Silk Fabric ◽  
The Matrix ◽  
The Stability

Unmodified natural rubber is not suitable for any elstomeric applications. Therefore, it is appropriate to modify natural rubber chemically to enhance the stability, which can be termed as vulcanization. Incorporation of fibers/fabrics is a common method to increase the stability of natural rubber along with chemical modification. Natural rubber-based composites have been prepared by the addition of silk fabric into natural rubber. The matrix material for the composite is glutaraldehyde cured natural rubber. Silk is an ecofriendly and biodegradable material with excellent tensile strength. When such kind of fabric is introduced into the vulcanized rubber as the matrix, all the physical properties were found to be enhanced considerably. Tensile properties in terms of ultimate tensile strength, elongation at break, and modulus of elasticity are measured for the composites of natural rubber/silk fabric at various glutaraldehyde concentrations. Thermogravimetric analysis and temperature scanning stress relaxation techniques are employed to evaluate the thermal stability of the resulting composites. Effects of glutaraldehyde addition on the physical properties of the composite were studied in detail. Considerable enhancement in the stability of natural rubber in terms of tensile properties, thermal stability, and solvent resistance is noticed up on the incorporation of silk fabric as well as glutaraldehyde curing.

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

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