scholarly journals Process Design Strategies for Producing Heavy Section Steel with Improved Quality

2013 ◽  
Vol 652-654 ◽  
pp. 988-991
Author(s):  
Jing Wei Zhao ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei ◽  
Chong Soo Lee
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Longitudinal Direction ◽  
Ring Rolling ◽  
Design Strategies ◽  
Noticeable Effect ◽  
Heavy Section ◽  
Microstructure And Mechanical Properties ◽  
Impact Energies ◽  
The Impact

Uniformity of microstructure and mechanical properties is required for the heavy section steel. In the present work, a heavy section wind tower flange was manufactured by controlled ring-rolling. Post-rolling heat treatment was employed to optimize the microstructure and mechanical properties. The chemical composition, microstructure and mechanical properties in different zones of the flange were investigated. The results showed that the chemical composition and microstructure were uniformly distributed in the flange. The tensile strength showed similar values in different sampling locations. The strain and impact energies of specimens prepared along the longitudinal direction were higher than that prepared along both the radius and thickness directions. Notch direction did not have noticeable effect on the impact energy. It is demonstrated that the designed process is effective for producing heavy section steel with improved quality.

scholarly journals Microstructure and mechanical properties of different keratinous horns

2018 ◽  
Vol 15 (143) ◽  
pp. 20180093 ◽  
Author(s):  
Yuchen Zhang ◽  
Wei Huang ◽  
Cheryl Hayashi ◽  
John Gatesy ◽  
Joanna McKittrick
Keyword(s):  
Mechanical Properties ◽  
Longitudinal Direction ◽  
Bighorn Sheep ◽  
Growth Direction ◽  
Ovis Aries ◽  
Domestic Sheep ◽  
Microstructure And Mechanical Properties ◽  
Mountain Goat ◽  
The Impact ◽  
Horn Core

Animal horns play an important role during intraspecific combat. This work investigates the microstructure and mechanical properties of horns from four representative ruminant species: the bighorn sheep ( Ovis canadensis ), domestic sheep ( Ovis aries ), mountain goat ( Oreamnos americanus ) and pronghorn ( Antilocapra americana ), aiming to understand the relation between evolved microstructures and mechanical properties. Microstructural similarity is found where disc-shaped keratin cells attach edge-to-edge along the growth direction of the horn core (longitudinal direction) forming a lamella; multiple lamellae are layered face to face along the impact direction (radial direction, perpendicular to horn core growth direction), forming a wavy pattern surrounding a common feature, the tubules. Differences among species include the number and shape of the tubules, the orientation of aligned lamellae and the shape of keratin cells. Water absorption tests reveal that the pronghorn horn has the largest water-absorbing ability due to the presence of nanopores in the keratin cells. The loading direction (compressive and tensile) and level of hydration vary among the horns from different species. The differences in mechanical properties among species may relate to their different fighting behaviours: high stiffness and strength in mountain goat to support the forces during stabbing; high tensile strength in pronghorn for interlocked pulling; impact energy absorption properties in domestic and bighorn sheep to protect the skull during butting. These design rules based on evolutionary modifications among species can be applied in synthetic materials to meet different mechanical requirements.

scholarly journals Microstructure and Properties of the Copper Alloyed with Ag and Ti Powders Using Fiber Laser

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2430 ◽  
Author(s):  
Mariusz Krupiński ◽  
Paulina Ewelina Smolarczyk ◽  
Mirosław Bonek
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Chemical Composition ◽  
Abrasion Resistance ◽  
Melting Zone ◽  
Hardness Measurement ◽  
Copper Surface ◽  
Laser Alloying ◽  
Microstructure And Mechanical Properties ◽  
The Impact

The scope of the work covers the development of the relationship between the chemical composition of surface-modified copper and the diffusion of alloy elements as well as the microstructure and mechanical properties. This article presents the impact of laser alloying with titanium and silver powders on the microstructure and mechanical properties of copper. In order to investigate the phenomena occurring during the laser alloying process, microstructural studies were performed using scanning electron microscopy (SEM), optical microscopy, and energy dispersive x-ray spectroscopic (EDS) analysis of the chemical composition in micro-areas. In addition, to test the properties of the resulting alloy, abrasion resistance, hardness measurement at low loading force, and conductivity measurements were performed. As a result of alloying with Ag and Ti powders, three distinct zones were indeed recognized: re-melting zone (RZ), diffusion zone (DZ), and heat affected zone (HAZ). The surface modification that results from laser alloying increases the hardness as well as the abrasion resistance of the material. Overall, it was found that laser alloying with Ti powder increased the strength of the copper surface layer due to the formation of intermetallic phases (Cu3Ti2). It was also found that laser alloying with Ag powder changed the mechanical properties of the surface layer due to the solid solution strengthening.

scholarly journals Microstructure and Mechanical Properties of Heat-Affected Zone of Repeated Welding AISI 304N Austenitic Stainless Steel by Gleeble Simulator

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 773
Author(s):  
Y.H. Guo ◽  
Li Lin ◽  
Donghui Zhang ◽  
Lili Liu ◽  
M.K. Lei
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Energy ◽  
Heat Affected Zone ◽  
Ferrite Content ◽  
Equipment Safety ◽  
Microstructure And Mechanical Properties ◽  
Δ Ferrite ◽  
The Impact

Heat-affected zone (HAZ) of welding joints critical to the equipment safety service are commonly repeatedly welded in industries. Thus, the effects of repeated welding up to six times on the microstructure and mechanical properties of HAZ for AISI 304N austenitic stainless steel specimens were investigated by a Gleeble simulator. The temperature field of HAZ was measured by in situ thermocouples. The as-welded and one to five times repeated welding were assigned as-welded (AW) and repeated welding 1–5 times (RW1–RW5), respectively. The austenitic matrices with the δ-ferrite were observed in all specimens by the metallography. The δ-ferrite content was also determined using magnetic and metallography methods. The δ-ferrite had a lathy structure with a content of 0.69–3.13 vol.%. The austenitic grains were equiaxial with an average size of 41.4–47.3 μm. The ultimate tensile strength (UTS) and yield strength (YS) mainly depended on the δ-ferrite content; otherwise, the impact energy mainly depended on both the austenitic grain size and the δ-ferrite content. The UTS of the RW1–RW3 specimens was above 550 MPa following the American Society of Mechanical Engineers (ASME) standard. The impact energy of all specimens was higher than that in ASME standard at about 56 J. The repeated welding up to three times could still meet the requirements for strength and toughness of welding specifications.

Residual Stresses in Intrinsic UD-CFRP-Steel-Laminates - Experimental Determination, Identification of Sources, Effects and Modification Approaches

2015 ◽  
Vol 825-826 ◽  
pp. 369-376 ◽  
Author(s):  
Robert Prussak ◽  
Daniel Stefaniak ◽  
Christian Hühne ◽  
Michael Sinapius
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Tensile Strength ◽  
Epoxy Composite ◽  
Thermal Residual Stress ◽  
Fiber Metal Laminates ◽  
Fiber Metal ◽  
Impact Energies ◽  
The Impact ◽  
Specific Impact

This paper focuses on the reduction of process-related thermal residual stress in fiber metal laminates and its impact on the mechanical properties. Different modifications during fabrication of co-cure bonded steel/carbon epoxy composite hybrid structures were investigated. Specific examinations are conducted on UD-CFRP-Steel specimens, modifying temperature, pressure or using a thermal expansion clamp during manufacturing. The impact of these parameters is then measured on the deflection of asymmetrical specimens or due yield-strength measurements of symmetrical specimens. The tensile strength is recorded to investigate the effect of thermal residual stress on the mechanical properties. Impact tests are performed to determine the influence on resulting damage areas at specific impact energies. The experiments revealed that the investigated modifications during processing of UD-CFRP-Steel specimens can significantly lower the thermal residual stress and thereby improve the tensile strength.

The Effect of Aging Heat Treatment on the Microstructure and Mechanical Properties of 10Cr20Ni25Mo1.5NbN Austenitic Steel

2016 ◽  
Vol 35 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Zhiyuan Liang ◽  
Wanhua Sha ◽  
Qinxin Zhao ◽  
Chongbin Wang ◽  
Jianyong Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Austenitic Steel ◽  
Treatment Time ◽  
Aging Treatment ◽  
Secondary Phases ◽  
Aging Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
The Impact

AbstractThe effect of aging heat treatment on the microstructure and mechanical properties of 10Cr20Ni25Mo1.5NbN austenitic steel was investigated in this article. The microstructure was characterized by scanning electron microscopy, energy dispersive spectrometry and transmission electron microscopy. Results show that the microstructure of 10Cr20Ni25Mo1.5NbN austenitic is composed of austenite. This steel was strengthened by precipitates of secondary phases that were mainly M23C6 carbides and NbCrN nitrides. As aging treatment time increased, the tensile strength first rose (0–3,000 h) and then fell (3,000–5,000 h) due to the decrease of high density of dislocations. The impact absorbed energy decreased sharply, causing the sulfides to precipitate at the grain boundary. Therefore, the content of sulfur should be strictly controlled in the steelmaking process.

scholarly journals Microstructure and Mechanical Properties of 14Cr-ODS Steels with Zr Addition

2019 ◽  
Vol 38 (2019) ◽  
pp. 404-410 ◽  
Author(s):  
Weijuan Li ◽  
Haijian Xu ◽  
Xiaochun Sha ◽  
Jingsong Meng ◽  
Zhaodong Wang
Keyword(s):  
Mechanical Properties ◽  
Hot Isostatic Pressing ◽  
Oxide Dispersion Strengthened ◽  
Nominal Composition ◽  
Ods Steel ◽  
Zr Addition ◽  
Microstructure And Mechanical Properties ◽  
The Matrix ◽  
Ods Steels ◽  
The Impact

AbstractIn this study, oxide dispersion strengthened (ODS) ferritic steels with nominal composition of Fe–14Cr–2W–0.35Y2O3 (14Cr non Zr-ODS) and Fe–14Cr–2W–0.3Zr–0.35Y2O3 (14Cr–Zr-ODS) were fabricated by mechanical alloying (MA) and hot isostatic pressing (HIP) technique to explore the impact of Zr addition on the microstructure and mechanical properties of 14Cr-ODS steels. Microstructure characterization revealed that Zr addition led to the formation of finer oxides, which was identified as Y4Zr3O12, with denser dispersion in the matrix. The ultimate tensile strength (UTS) of the non Zr-ODS steel is about 1201 MPa, but UTS of the Zr-ODS steel increases to1372 MPa, indicating the enhancement of mechanical properties by Zr addition.

scholarly journals Influence of Vanadium on the Microstructure and Mechanical Properties of Medium-Carbon Steels for Wheels

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 978 ◽  
Author(s):  
Pengfei Wang ◽  
Zhaodong Li ◽  
Guobiao Lin ◽  
Shitong Zhou ◽  
Caifu Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Grain Refinement ◽  
Carbon Steels ◽  
Precipitation Strengthening ◽  
Austenite Grain Size ◽  
Medium Carbon ◽  
Microstructure And Mechanical Properties ◽  
Medium Carbon Steels ◽  
The Impact

Steels used for high-speed train wheels require a combination of high strength, toughness, and wear resistance. In 0.54% C-0.9% Si wheel steel, the addition of 0.075 or 0.12 wt % V can refine grains and increase the ferrite content and toughness, although the influence on the microstructure and toughness is complex and poorly understood. We investigated the effect of 0.03, 0.12, and 0.23 wt % V on the microstructure and mechanical properties of medium-carbon steels (0.54% C-0.9% Si) for train wheels. As the V content increased, the precipitation strengthening increased, whereas the grain refinement initially increased, and then it remained unchanged. The increase in strength and hardness was mainly due to V(C,N) precipitation strengthening. Increasing the V content to 0.12 wt % refined the austenite grain size and pearlite block size, and increased the density of high-angle ferrite boundaries and ferrite volume fraction. The grain refinement improved the impact toughness. However, the impact toughness then reduced as the V content was increased to 0.23 wt %, because grain refinement did not further increase, whereas precipitation strengthening and ferrite hardening occurred.

Microstructure and Mechanical Properties of Al-12.6%Si Composite Reinforced by Al63Cu25Fe12Quasicrystal

2012 ◽  
Vol 182-183 ◽  
pp. 162-166
Author(s):  
Can Can Li ◽  
Hao Ran Geng ◽  
Zhen Yuan Li ◽  
Hai Ou Qin
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Cooling Rate ◽  
Quasicrystalline Phase ◽  
Melt Temperature ◽  
Microstructure And Mechanical Properties

In this paper, Al-12.6%Si/Al63Cu25Fe12 composites were fabricated by method of casting. The microstructure and chemical composition of Al63Cu25Fe12 quasicrystal alloy and Al-12.6%Si alloy reinforced by the quasicrystal were studied, and the mechanical properties of Al-12.6%Si composite were also measured. The results show that almost single quasicrystalline phases exist in the samples which are cast with the 1300°C melt. Quickly enough cooling rate and appropriate melt temperature are necessary for the formation of the quasicrystalline phase. In addition, Al-12.6%Si composite has optimal mechanical properties when the amount of Al63Cu25Fe12 quasicrystal is 3 wt%.

Effect of Tempering Time on Microstructure and Mechanical Properties of SA738 Gr.B Steel

2021 ◽  
Vol 1016 ◽  
pp. 1739-1746
Author(s):  
Yan Mei Li ◽  
Shu Zhan Zhang ◽  
Zai Wei Jiang ◽  
Sheng Yu ◽  
Qi Bin Ye ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Yield Strength ◽  
Microstructure Evolution ◽  
Impact Energy ◽  
Nuclear Power ◽  
Microstructure And Mechanical Properties ◽  
The Impact ◽  
Tempering Time

The effect of tempering time on the microstructure and mechanical properties of SA738 Gr.B nuclear power steel was studied using SEM, TEM and thermodynamic software, and its precipitation and microstructure evolution during tempering were clarified. The results showed that SA738 Gr.B nuclear power steel has better comprehensive mechanical properties after tempering at 650 °C for 1h. With the extension of the tempering time, M3C transformed into M23C6 with increasing size, which affected the yield strength and impact energy. When the tempering time is 8h ~ 10h, due to the transformation of M3C to M23C6, the composition of matrix around the carbide changed, causing the temperature of Ac1 dropped, forming twin-martensite which deteriorated the impact toughness of the steel.

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