Effects of Stress-Relief Annealing on the Residual Stress and the Microstructure of TA15 Welded Joint

2016 ◽  
Vol 849 ◽  
pp. 281-286 ◽  
Author(s):  
Teng Ma ◽  
Xiao Yun Song ◽  
Wen Jun Ye ◽  
Song Xiao Hui ◽  
Rui Liu
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Fusion Zone ◽  
Maximum Stress ◽  
Electron Beam Welding ◽  
Welded Joint ◽  
Stress Relief ◽  
Welding Zone ◽  
Weave Structure ◽  
Effects Of Stress

The effects of stress-relief annealing on the distribution of residual stress and on the microstructure of TA15 (Ti-6.5Al-2Zr-1Mo-1V) alloy joints by electron beam welding (EBW) were investigated. The results indicated that the microstructure of welded joint presented a transitional change, i.e. basket-weave structure appeared in the fusion zone while equiaxed α structure in base metal. No significant change occurred in microstructure after annealing at 650°C for 2 h. The residual stress in fusion zone was mainly tensile stress and the maximum longitudinal stress value was 473MPa. After annealing, the residual stress near the welded joint exhibited a uniform distribution and the maximum stress droped to 150 MPa. The yield stress and tensile stress of the TA15 welding zone were 1016 MPa and 1100 MPa respectively.

Effects of Ultrasonic Impact Treatment on the Residual Stress and Microstructure of TA15 Welded Joint

2017 ◽  
Vol 898 ◽  
pp. 1056-1062 ◽  
Author(s):  
Guang Lu Qian ◽  
Xiao Yun Song ◽  
Wen Jun Ye ◽  
Rong Chen ◽  
Teng Ma ◽  
...  
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Fusion Zone ◽  
Maximum Stress ◽  
Electron Beam Welding ◽  
Welded Joint ◽  
Maximum Tensile Stress ◽  
Residual Stress Distribution ◽  
Longitudinal Stress ◽  
Ultrasonic Impact Treatment

The effects of ultrasonic impact treatment (UIT) on the distribution of residual stress and on the microstructure of TA15 (Ti-6.5Al-2Zr-1Mo-1V) alloy joints by electron beam welding (EBW) were investigated. The results demonstrated that a marked microstructure change occurred after welding and the microstructure of welded joint presented a transitional change, i.e. martensite appeared in the fusion zone while equiaxed α in base mental. The residual stress in fusion zone was mainly tensile stress, and the maximum longitudinal stress value was 817MPa, which located in the centerline of welded joint. The results indicated that different impact methods have different influence on residual stress distribution. After employing UIT on welding toe, the residual stress near the welded joint exhibited a uniform distribution and the maximum tensile stress dropped to-153MPa. While after applying UIT on full coverage, the curve of the residual stress was steep and the maximum stress was still tensile stress. After UIT, no significant change occurred in microstructure and the tensile strength has a little change.

Tempering effect on residual stress in bimetallic roll

2021 ◽  
pp. 2140044
Author(s):  
Nao-Aki Noda ◽  
Mohd Radzi Aridi ◽  
Yoshikazu Sano
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Maximum Stress ◽  
Work Roll ◽  
Nonuniform Heating ◽  
Roll Surface ◽  
Uniform Heating ◽  
Heating Treatment ◽  
Quenching And Tempering

In this study, tempering effect on the residual stress is studied after uniform heating–quenching and nonuniform heating–quenching for bimetallic work roll. Results for uniform heating treatment showed that the maximum stress at the center decreases by 68% from 396 MPa to 126 MPa after the first and second tempering. Results for nonuniform heating treatment showed that the maximum stress at the center decreases by 47% from 309 MPa to 165 MPa after the first and second tempering. It may be concluded that nonuniform heating–quenching and tempering are useful for reducing the central tensile stress preventing cracks at the roll surface.

Mechanical Properties of Forged Ti-6Al-4V Structure by Electron Beam Welding

2012 ◽  
Vol 455-456 ◽  
pp. 308-313
Author(s):  
Hong Yu Qi ◽  
Jian Xie ◽  
Shao Lin Li ◽  
Xiao Guang Yang
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Fusion Zone ◽  
Electron Beam Welding ◽  
Welded Joint ◽  
Base Material ◽  
Structure Design ◽  
Large Gradient ◽  
Welded Structure ◽  
Aero Engine

The blisk (bladed disk) is a new structural component of the modern aero-engine and plays an important role in improving its performance. Ti-6Al-4V alloy joints welded by electron beam have been widely used for compressor blisk in advanced aero engine. It is necessary to analyze microstructure and mechanical properties of Ti-6Al-4V welded structure by electron beam welding (EBW) for failure analysis and structure design of blisk. Microstructure of Ti-6Al-4V welded structure by EBW was investigated by microscopic observation and micro indentation testing. Experiment results show grain coarsening in fusion zone (FZ) and heat affected zone (HAZ) appears large gradient organization structure, which presents significant local heterogeneity. On the centerline perpendicular to the welding direction, Vickers microhardness was measured in increments of 1mm, 0.5mm, 0.25mm and 0.1mm. Due to the presence of martensite, microhardness of the fusion zone is about 20% higher than that of the base material. The size of joints in different regions was acquired, 2.5 to 3.0-mm-wide in FZ and about 0.7-mm-wide in HAZ respectively. Three different types of EBW samples were designed for tensile test, including welded structure, welded joint and base material. Three different stress-strain curves of specimens were acquired, including welded joint. The experiment data indicates that the tensile strength of welded joints is 8% more than that of the base metal.

Relation between Residual Stresses in TBCs Interface Area with TGO Interface Morphology

2012 ◽  
Vol 151 ◽  
pp. 469-473 ◽  
Author(s):  
Zhi Yong Han ◽  
Hua Zhang
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Residual Stresses ◽  
Compressive Stress ◽  
Bond Coat ◽  
Maximum Stress ◽  
Ceramic Coating ◽  
Interface Morphology ◽  
Interface Area ◽  
Symmetrical Center

Considering the thermally-growth oxide (TGO) that grows between top ceramic coating (TCC)and bond coat (BC) interface and surface morphology of bond coat in a TBC system, the effect of residual stresses distribution by actual and assuming interface morphology in TGO area was calculated with ABAQUS. The calculating result shows that the residual stress of TCC/TGO and TGO/TCC interface are affected by interface morphology obviously, σyy is tensile at peaks and compressive at valleys for both with maximum stress beside the symmetrical center and at the symmetrical center respectively. σyy stress in TCC is bigger than that of BC for both. σxx stress of actual TGO in the three layers remains the same, the interim area change dramatically with TCC layer compressive stress, TGO layer smaller compressive stress, BC layer tensile stress.

The effect of differential thermal expansion on residual stresses in a welded connection

1976 ◽  
Vol 11 (1) ◽  
pp. 56-61
Author(s):  
E Procter ◽  
E M Beaney
Keyword(s):  
Residual Stress ◽  
Thermal Expansion ◽  
Residual Stresses ◽  
Welded Joint ◽  
Stress Relief ◽  
Apparent Strain ◽  
Differential Thermal Expansion ◽  
Strain Gauge Measurements ◽  
Welded Connection ◽  
Differential Expansion

Two tests were conducted on a welded joint between a forging and a pipe adaptor, to investigate the effect of differential thermal expansion in the various parts of the joint, on the residual stress. The first test was carried out with the weld in the approved manufacturing stress relieved condition. The second test was carried out following normalizing and extended stress relief heat treatments. Strain gauge measurements were made on the heat affected zones and at various positions across the weld as the forging was heated and cooled through approximately 250° C. The apparent strain outputs of the gauges used at each location were determined from gauges attached to ‘stress free islands’ machined in the weld at the required postions Since the tests could only be carried out over a 250° C range the results were linearly extrapolated to cover the range of stress relief temperatures. It is shown that differential expansion can have significant effects on residual weld stresses as the structures are temperature cycled.

TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

1994 ◽  
Vol 52 ◽  
pp. 628-629
Author(s):  
J. Fang ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Residual Stress ◽  
Single Phase ◽  
Stress Relief ◽  
Stress Recovery ◽  
Surface Residual Stress ◽  
Microscopic Mechanism ◽  
Sic Particles ◽  
Annealing Procedure ◽  
The Difference ◽  
Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

Influence of the Welded Joint on the Mechanical Behavior of Steel Piles during Static and Dynamic Deformation

2007 ◽  
Vol 345-346 ◽  
pp. 1469-1472
Author(s):  
Gab Chul Jang ◽  
Kyong Ho Chang ◽  
Chin Hyung Lee
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Mechanical Behavior ◽  
Welded Joint ◽  
Dynamic Deformation ◽  
Three Dimensional ◽  
Steel Structures ◽  
Residual Stress Distribution ◽  
Dynamic Mechanical Behavior ◽  
Steel Piles

During manufacturing the welded joint of steel structures, residual stress is produced and weld metal is used inevitably. And residual stress and weld metal influence on the static and dynamic mechanical behavior of steel structures. Therefore, to predict the mechanical behavior of steel pile with a welded joint during static and dynamic deformation, the research on the influence of the welded joints on the static and dynamic behavior of steel pile is clarified. In this paper, the residual stress distribution in a welded joint of steel piles was investigated by using three-dimensional welding analysis. The static and dynamic mechanical behavior of steel piles with a welded joint is investigated by three-dimensional elastic-plastic finite element analysis using a proposed dynamic hysteresis model. Numerical analyses of the steel pile with a welded joint were compared to that without a welded joint with respect to load carrying capacity and residual stress distribution. The influence of the welded joint on the mechanical behavior of steel piles during static and dynamic deformation was clarified by comparing analytical results

Residual Stress Measurement in Silicon Substrate After Local Thermal Oxidation Using Microscopic Raman Spectroscopy

1991 ◽  
Vol 226 ◽  
Author(s):  
Hideo Miura ◽  
Hiroshi Sakata ◽  
Shinji Sakata Merl
Keyword(s):  
Residual Stress ◽  
Raman Spectroscopy ◽  
Tensile Stress ◽  
Oxide Film ◽  
Film Thickness ◽  
Silicon Dioxide ◽  
Thermal Oxidation ◽  
Silicon Substrate ◽  
Nitride Film ◽  
Oxide Film Thickness

AbstractThe residual stress in silicon substrates after local thermal oxidation is discussed experimentally using microscopic Raman spectroscopy. The stress distribution in the silicon substrate is determined by three main factors: volume expansion of newly grown silicon–dioxide, deflection of the silicon–nitride film used as an oxidation barrier, and mismatch in thermal expansion coefficients between silicon and silicon dioxide.Tensile stress increases with the increase of oxide film thickness near the surface of the silicon substrate under the oxide film without nitride film on it. The tensile stress is sometimes more than 100 MPa. On the other hand, a complicated stress change is observed near the surface of the silicon substrate under the nitride film. The tensile stress increases initially, as it does in the area without nitride film on it. However, it decreases with the increase of oxide film thickness, then the compressive stress increases in the area up to 170 MPa. This stress change is explained by considering the drastic structural change of the oxide film under the nitride film edge during oxidation.

Sign in / Sign up

Export Citation Format

Share Document