The size effect of martensite laths and precipitates on high strength wear-resistant steels

2021 ◽  
Author(s):  
Huan Xue ◽  
Yansong Zhang ◽  
Min Zhu ◽  
Xiyan Yin ◽  
Wenqian Zhang ◽  
...  
Keyword(s):  
Low Cost ◽  
High Strength ◽  
Middle Layer ◽  
Martensite Lath ◽  
Precipitate Size ◽  
Wear Resistant ◽  
High Toughness ◽  
Strength Difference ◽  
The Impact ◽  
Internal Relationship

Abstract Low alloy high strength wear resistant steels are with high toughness, low cost and good abrasion resistance. It can effectively resist the propagation of wear cracks and prolong the service life of machine components. This paper focuses on the internal relationship between macroscopic physical properties and microscopic martensite lath and precipitate size throughout thickness of wear resistant steel. Four kinds of 40mm thickness wear resistant steels with different alloy chemical composition were produced and investigated. Results show the strength and hardness performance of ARIV are obviously higher than other three steels. ARI have a relatively large strength difference through thickness. The impact toughness of ARIV is relatively uniform, which is greater than that of the ARIII at middle layer and lower than that of the ARIII at 1/4 layer. The width of martensite lath of ARIV is relatively small, mainly 100 ~ 300 nm，while that of ARII and ARIII is mainly 200 ~400 nm. ARIV steel has shorter martensite lath band and more precipitates below 50 nm. It indicates that the size of martensite laths and precipitates of wear-resistant steels are important factors to determine its performance throughout thickness.

Fishing line artificial muscle reinforced composite for impact mitigation and on-demand damage healing

2016 ◽  
Vol 50 (30) ◽  
pp. 4235-4249 ◽  
Author(s):  
Pengfei Zhang ◽  
Guoqiang Li
Keyword(s):  
Low Cost ◽  
Syntactic Foam ◽  
Artificial Muscle ◽  
High Strength ◽  
Composite Panel ◽  
On Demand ◽  
Healing Efficiency ◽  
Foam Composite ◽  
Damage Healing ◽  
The Impact

In this study, a fishing line artificial muscle reinforced syntactic foam composite was investigated. About 3.5 vol.% of polymer artificial muscle was woven into a two-dimensional grid skeleton and embedded into a syntactic foam matrix. The grid-stiffened syntactic foam composite was designed to be able to repeatedly heal cracks on-demand. Short thermoplastic fibers were also dispersed into the foam matrix both as reinforcement and as a healing agent. The composite panel was repeatedly impacted, bending fractured, and healed as per the biomimetic close-then-heal strategy. It is found that the composite panel responds to impact quasi-statically. The impact- and bending-induced macroscopic cracks can be repeatedly healed with high healing efficiency, under both free and clamped boundary conditions. Contrary to most healing systems, the healing efficiency within the damage–healing cycles in this study increases as the damage-healing cycle increases. Because the artificial muscle is made of low-cost and high-strength fishing line, it is envisioned that the composite panel developed in this study may be a viable alternative core for healable lightweight composite sandwich structures at competitive cost.

scholarly journals Effect of Carbon Partitioning, Carbide Precipitation, and Grain Size on Brittle Fracture of Ultra-High-Strength, Low-Carbon Steel after Welding by a Quenching and Partitioning Process

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 747 ◽  
Author(s):  
Farnoosh Forouzan ◽  
M. Guitar ◽  
Esa Vuorinen ◽  
Frank Mücklich
Keyword(s):  
Grain Size ◽  
Carbon Steel ◽  
Weld Zone ◽  
Low Carbon Steel ◽  
High Strength ◽  
Precipitate Size ◽  
Low Carbon ◽  
Quenching And Partitioning ◽  
High Level ◽  
The Impact

To improve the weld zone properties of Advanced High Strength Steel (AHSS), quenching and partitioning (Q&P) has been used immediately after laser welding of a low-carbon steel. However, the mechanical properties can be affected for several reasons: (i) The carbon content and amount of retained austenite, bainite, and fresh martensite; (ii) Precipitate size and distribution; (iii) Grain size. In this work, carbon movements during the partitioning stage and prediction of Ti (C, N), and MoC precipitation at different partitioning temperatures have been simulated by using Thermocalc, Dictra, and TC-PRISMA. Verification and comparison of the experimental results were performed by optical microscopy, X-ray diffraction (XRD), Scanning Electron Microscop (SEM), and Scanning Transmission Electron Microscopy (STEM), and Energy Dispersive Spectroscopy (EDS) and Electron Backscatter Scanning Diffraction (EBSD) analysis were used to investigate the effect of martensitic/bainitic packet size. Results show that the increase in the number density of small precipitates in the sample partitioned at 640 °C compensates for the increase in crystallographic packets size. The strength and ductility values are kept at a high level, but the impact toughness will decrease considerably.

Effect of Tempering Temperature on Mechanical Properties of High Strength Wear Resistant Cast Steel

2013 ◽  
Vol 791-793 ◽  
pp. 440-443
Author(s):  
Hong Bo Li ◽  
Jing Wang ◽  
Han Chi Cheng ◽  
Chun Jie Li ◽  
Xing Jun Su
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Cast Steel ◽  
High Strength ◽  
Fracture Morphology ◽  
Temperature Quenching ◽  
Tempering Temperature ◽  
Wear Resistant ◽  
Dimple Fracture ◽  
The Impact

This paper mainly studied the high temperature quenching oil quenching, tempering temperature on the influence of high strength steel mechanical properties of wear resistant. The results show that high strength and toughness wear-resistant cast steel with 880°C× 30min after oil quenching, the hardness of 38.6HRC steel, the impact toughness value reaches 40.18J/cm2. After 200°C, 400°C and 600°C tempering, with the increase of the tempering temperature, the hardness decreased linearly, as by 600°C tempering, the hardness has been reduced to 22.3HRC. Impact toughness with the tempering temperature, the overall upward trend, the impact toughness of some reduced at 400°C, the highest impact toughness value reaches 113.34J/cm2. From the fracture morphology can be seen, with the increase of tempering temperature, ductile fracture increased, by 600°C tempering is dimple fracture, obviously can not see the traces of brittle fracture.

Experimental and numerical study of the dynamic response of an adhesively bonded automotive structure

2020 ◽  
Vol 234 (14) ◽  
pp. 3385-3397
Author(s):  
NDD Silva ◽  
JJM Machado ◽  
EAS Marques ◽  
PMGP Moreira ◽  
LFM da Silva
Keyword(s):  
Adhesive Bonding ◽  
Numerical Study ◽  
Low Cost ◽  
High Strength ◽  
Epoxy Adhesive ◽  
Lap Joints ◽  
Impact Response ◽  
Vehicle Body ◽  
Component Level ◽  
The Impact

Based on economic and environmental factors related to energy efficiency, the automotive industry is being increasingly encouraged to design lighter structures, making use of adhesive bonding in vehicle body frames. To meet the standards of the automotive sector, adhesive joints must provide high strength and stiffness, low cost and good energy absorption at a component level, thereby ensuring good impact strength and passenger safety. This work aims to study, at room temperature (24°C), the impact response of a real scale automotive structure bonded with a crash-resistant epoxy, allowing to access the suitability of adhesives for automotive structural purposes. The epoxy adhesive was found to successfully transfer the loads to the aluminium substrates and not to compromise the integrity of the structure, as its failure was dominated by the behaviour of aluminium. Results obtained with a numerical model of the component were found to be in close agreement with the experimental failure load, demonstrating that numerical analysis can be a viable tool to predict the structure’s behaviour. In addition, a polyurethane was used as an alternative to the epoxy system to bond the structure, proving that the joint behaves better in the presence of a more flexible adhesive, as no failure was found for this case. Aluminium single-lap joints with two adhesive thicknesses were tested as a complement to understand the influence of this parameter on the impact response of a joint, showing a 21% decrease in strength when the highest thickness was used.

The Preparation and Performance of Wear-Resistant Coatings

2013 ◽  
Vol 833 ◽  
pp. 378-382
Author(s):  
Cheng Zhang ◽  
Yue Ting Ding ◽  
Xia Sun ◽  
Shu Guang Wang
Keyword(s):  
Low Cost ◽  
High Strength ◽  
Good Effect ◽  
Polymeric Coatings ◽  
Reinforced Polymers ◽  
Wear Resistant ◽  
Wear Resistant Coatings ◽  
Damage And Failure ◽  
And Performance ◽  
Commercial Applications

Polymers and their composites are extensively used in commercial applications[.Wearing is one of the forms which makes materials damage and failure, especially the materials by friction, impact, erosion like rocks, minerals etc, the wear caused huge losses. Therefore, high-strength wear-resistant engineering machinery rational use of materials is very important. So chose a method that simple, rapid, low cost, good effect to prevent and repair the parts wear is necessary. In recent years, there has been much interest in particle-reinforced polymers not only because to produce this kind of polymer is cheaper, but also they can be used as high quality engineering materials[2]. In abrasive wear, the low stress also occupied a certain proportion of erosion[. Current polymeric coatings, although corrosion resistant, do not satisfactorily resist wear, but these studies provided many ways to improve the erosion resistance of particle-reinforced polymers[410].

scholarly journals The Effect of Addition of Bambusa Arundinacea (Retz.) Willd. Fibers to Heat-Cured Acrylic Resin on Impact Strength

2018 ◽  
Vol 1 (2) ◽  
pp. 81
Author(s):  
Chanita Elonianty ◽  
Titien Hary Agustantina ◽  
Intan Nirwana
Keyword(s):  
Impact Strength ◽  
Low Cost ◽  
Acrylic Resin ◽  
Test Results ◽  
High Toughness ◽  
Significant Difference ◽  
Impact Tester ◽  
Strength Formula ◽  
The Impact ◽  
One Way Anova

Background: The prevalence of acrylic resin dentures fracture due to accidental drop is relatively high especially when it is being cleaned by patient. The effort to strengthen acrylic resin denture was done by adding Bambusa arundinacea (Retz.) Willd fibers, which was based on previous research. It has been proven that the addition of bamboo fiber to self-cured acrylic resin can increase the tensile strength. It has acceptable tensile properties, relatively low cost, high toughness, and good thermal properties. Purpose: To determine the impact strength of heat-cured acrylic resin after the addition of Bambusa arundinacea (Retz.) Willd. fibers at various lengths and weights. Methods: Bambusa arundinacea (Retz.) Willd. fibers with lengths of 2 mm, 6 mm, 12 mm and weights of 3wt%, 6wt%, 9wt% were added to heat-cured acrylic resin. The impact strength of heat-cured acrylic resin was tested using the Charpy method with mini impact tester KRY type. The test results were calculated using the impact strength formula. The research data were analyzed using one-way anova test and Tukey HSD test. Results: The data analysis showed that there was a significant difference in impact strength of heat-cured acrylic resin after the addition of Bambusa arundinacea (Retz.) Willd fibers. Conclusion: Addition of Bambusa arudinacea (Retz.) Willd. fibers increased the impact strength of heat-cured acrylic resin respective to the increment of length and weight of Bambusa arudinacea (Retz.) Willd. fibers.

Effect of Alloy Addition on Mechanical Properties and Decarburization Sensitivity of Spring Steel

2012 ◽  
Vol 476-478 ◽  
pp. 188-193
Author(s):  
Jun Tian ◽  
Shun Xue ◽  
Guo Guang Cheng ◽  
Kuo Chih Chou
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Energy ◽  
Induction Furnace ◽  
High Strength ◽  
Spring Steel ◽  
Vacuum Induction Furnace ◽  
High Toughness ◽  
Alloy Addition ◽  
The Impact

The mechanical properties and decarburization layer depths after heat treatment have been investigated for the experimental steels，which were melted by means of 10Kg vacuum induction furnace in the laboratory . It has been confirmed that additions of silicon and vanadium can improve strength of the steels and, the tensile strength of the steels increases with silicon content from 1.4% up to 2.0%. The reduction of carbon content and the addition of carbide forming elements decrease the decarburization sensitivity of the steels tested. The tensile strengths of the steels with carbon less than 0.5% are between 1016.88 to 1674.64 MPa, and the impact energy between 15.50 to 34.50 J, which are compared with the tensile strength of 1160.89MPa, the impact energy of 19.00 J for 55SiCrV. The steels with optimized compositions, which consists of 0.4~0.5% C, 1.6~2.0% Si, 0.8% Cr, 0.2% V, have a satisfactory property with high strength, high toughness and good anti-decarburization.

Decomposition of the metastable beta titanium alloy Ti-15-3

1983 ◽  
Vol 41 ◽  
pp. 264-265
Author(s):  
Y. L. Chen ◽  
S. Fujlshiro
Keyword(s):  
Low Cost ◽  
High Strength ◽  
Alpha Phase ◽  
Thick Sheet ◽  
Omega Phase ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Beta Matrix ◽  
Metastable Beta ◽  
Very High

Metastable beta titanium alloys have been known to have numerous advantages such as cold formability, high strength, good fracture resistance, deep hardenability, and cost effectiveness. Very high strength is obtainable by precipitation of the hexagonal alpha phase in a bcc beta matrix in these alloys. Precipitation hardening in the metastable beta alloys may also result from the formation of transition phases such as omega phase. Ti-15-3 (Ti-15V- 3Cr-3Al-3Sn) has been developed recently by TIMET and USAF for low cost sheet metal applications. The purpose of the present study was to examine the aging characteristics in this alloy.The composition of the as-received material is: 14.7 V, 3.14 Cr, 3.05 Al, 2.26 Sn, and 0.145 Fe. The beta transus temperature as determined by optical metallographic method was about 770°C. Specimen coupons were prepared from a mill-annealed 1.2 mm thick sheet, and solution treated at 827°C for 2 hr in argon, then water quenched. Aging was also done in argon at temperatures ranging from 316 to 616°C for various times.

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

Advancing dairy farming profitability through research

2001 ◽  
pp. 17-22
Author(s):  
J.R. Caradus ◽  
D.A. Clark
Keyword(s):  
Research And Development ◽  
Dairy Cow ◽  
Low Cost ◽  
Pasture Management ◽  
Nitrogen Fertiliser ◽  
Grass Endophyte ◽  
Forage Species ◽  
Development Outcomes ◽  
Dairy Cow Nutrition ◽  
The Impact

The New Zealand dairy industry recognises that to remain competitive it must continue to invest in research and development. Outcomes from research have ensured year-round provision of low-cost feed from pasture while improving productivity. Some of these advances, discussed in this paper, include the use of white clover in pasture, understanding the impacts of grass endophyte, improved dairy cow nutrition, the use of alternative forage species and nitrogen fertiliser to improve productivity, demonstration of the impact of days-in-milk on profitability, and the use of feed budgeting and appropriate pasture management. Keywords: dairy, profitability, research and development

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