scholarly journals Thermal Stress Relaxation and High-Temperature Corrosion of Cr-Mo Steel Processed Using Multifunction Cavitation

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2291 ◽  
Author(s):  
Masataka Ijiri ◽  
Norihiro Okada ◽  
Syouta Kanetou ◽  
Masato Yamamoto ◽  
Daisuke Nakagawa ◽  
...  
Keyword(s):  
Residual Stress ◽  
High Temperature ◽  
Compressive Residual Stress ◽  
Crack Formation ◽  
High Temperature Corrosion ◽  
Thermal Shrinkage ◽  
Thermal Cycling Test ◽  
The Difference ◽  
Thermal Stress Relaxation ◽  
Reaction Vessels

This research investigated high-temperature corrosion (500 °C) of Cr-Mo steel processed using water jet peening or multifunction cavitation (MFC), and the suitability of such steel for high-temperature boilers and reaction vessels. High-temperature corrosion was induced using an embedment test and a coating test using sulfide-type K2SO4-Na2SO4 powder. To measure the relaxation of the residual stress due to the decrease in work hardening caused by an increase in specimen temperature and the difference in thermal shrinkage between the surface and interior of the specimen, a thermal cycling test was conducted. For the MFC-processed specimen, the oxide film that formed on the surface suppressed mass loss, prevented crack formation, and reduced the compressive residual stress caused by high-temperature corrosion. MFC-processed Cr-Mo steel is thus suitable for a high-temperature corrosion environment.

scholarly journals Thermal Stress Relaxation and High-Temperature Corrosion of Cr-Mo Steel Processed Using Multifunction Cavitation

2018 ◽  
Author(s):  
Masataka Ijiri ◽  
Norihiro Okada ◽  
Syouta Kanetou ◽  
Masato Yamamoto ◽  
Daisuke Nakagawa ◽  
...  
Keyword(s):  
Residual Stress ◽  
High Temperature ◽  
Compressive Residual Stress ◽  
Crack Formation ◽  
High Temperature Corrosion ◽  
Thermal Shrinkage ◽  
Thermal Cycling Test ◽  
The Difference ◽  
Thermal Stress Relaxation ◽  
Reaction Vessels

This research investigated high-temperature corrosion (500 °C) of Cr-Mo steel processed using water jet peening or multifunction cavitation (MFC), and the suitability of such steel for high-temperature boilers and reaction vessels. High-temperature corrosion was induced using an embedment test and a coating test using sulfide-type K2SO4-Na2SO4 powder. To measure the relaxation of the residual stress due to the decrease in work hardening caused by an increase in specimen temperature and the difference in thermal shrinkage between the surface and interior of the specimen, a thermal cycling test was conducted. For the MFC-processed specimen, the oxide film that formed on the surface suppressed mass loss, prevented crack formation, and reduced the compressive residual stress caused by high-temperature corrosion. MFC-processed Cr-Mo steel is thus suitable for a high-temperature corrosion environment.

Heat Treatment Effects on Distortion, Residual Stress, and Retained Austenite in Carburized 4320 Steel

2014 ◽  
Vol 783-786 ◽  
pp. 692-697 ◽  
Author(s):  
Andrew Clark ◽  
Randy J. Bowers ◽  
Derek O. Northwood
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Retained Austenite ◽  
Compressive Residual Stress ◽  
Surface Residual Stress ◽  
Depth Profiles ◽  
Size And Shape ◽  
Austenite Content ◽  
Treatment Conditions ◽  
The Difference

The effects of heat treatment on distortion, residual stress, and retained austenite were compared for case-carburized 4320 steel, in both the austempered and quench-and-tempered condition. Navy C-ring samples were used to quantify both size and shape distortions, as well as residual stress. The austempering heat treatment produced less distortion and a higher surface residual stress. Both hoop and axial stresses were measured; the difference between them was less than seven percent in all cases. Depth profiles were obtained for residual stress and retained austenite from representative C-ring samples for the austempered and quench-and-tempered heat treatment conditions. Austempering maintained a compressive residual stress to greater depths than quench-and-tempering. Quench-and-tempering also resulted in lower retained austenite amounts immediately beneath the surface. However, for both heat treatments, the retained austenite content was approximately one percent at depths greater than 0.5 mm.

Long Term Stability Evaluation of Stress Improvement Effect on Ni-Based Alloy Welds by Various Residual Stress Improvement Methods

2021 ◽  
Vol 1016 ◽  
pp. 819-825
Author(s):  
Li Na Yu ◽  
Kazuyoshi Saida ◽  
Masahito Mochizuki ◽  
Kazutoshi Nishimoto ◽  
Naoki Chigusa
Keyword(s):  
Residual Stress ◽  
High Temperature ◽  
Stress Relaxation ◽  
Compressive Residual Stress ◽  
Alloy 600 ◽  
Pressurized Water ◽  
Residual Stress Relaxation ◽  
Temperature Environment ◽  
Water Reactors ◽  
High Temperature Environment

Stress corrosion cracking (SCC) is one of serious aging degradation problems for the Alloy 600 components of pressurized water reactors (PWRs). In order to prevent SCC, various methods such as water jet peening (WJP), laser peening (LP), surface polishing have been used to introduce compressive stresses at the surfaces of the PWR components. However, it has been reported that such compressive residual stress introduced by these methods might be relaxed during the practical operation, because of high temperature environment. In this study, the hardness reduction behavior of the Alloy 600 processed by LP, Buff and WJP in the thermal aging process has been investigated to estimate the stability of the residual stress improving effect by each method, based on the fact that there is a correlation between the compressive residual stress relaxation and the decrease of hardness. The behavior of the residual stress relaxation in the processed materials in the high temperature environment has been discussed with kinetic analysis.

Reliability of Cu to Cu Joints Fabricated Using SnAg Capping Layer for 3D TSV Applications

2014 ◽  
Vol 900 ◽  
pp. 711-714 ◽  
Author(s):  
Sung Woo Ma ◽  
Jeong Hwan Lee ◽  
Jin Su Lee ◽  
Ki Bum Kim ◽  
Min Suk Suh ◽  
...  
Keyword(s):  
High Temperature ◽  
Contact Resistance ◽  
Crack Formation ◽  
Thermal Cycling Test ◽  
Capping Layer ◽  
High Temperature Storage ◽  
Bonding Technology ◽  
3D Chip Stacking ◽  
Solder Layer ◽  
Temperature Storage

Chip to Chip bonding technology using Cu bumps with solder capping layer has been widely investigated for 3D chip stacking applications. We studied the reliability of the Cu joints. Cu bumps capped with Sn-Ag solder layer were joined to bare Cu pads or Au/Ni electroplated Cu pads at 300°C for 10 sec after dispensing non-conductive paste (NCP). After joining, there were no failed joints and the contact resistance of the joints was very low in all specimens. High temperature storage (HTS) test (120°C, up to 2000 hrs) results demonstrated that the reliability was good in all specimens, while thermal cycling test (-55°C /+125°C, up to 2500 cycles) results showed that the contact resistance of the joints increased quickly after 2000 cycles which was attributed the crack formation in the joint interfaces.

Residual Stresses in Austenitic Stainless Steel due to High Strain Rate

2011 ◽  
Vol 681 ◽  
pp. 278-283 ◽  
Author(s):  
Kenji Suzuki ◽  
Takahisa Shobu
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Strain Rate ◽  
Compressive Residual Stress ◽  
Tensile Deformation ◽  
X Rays ◽  
Lattice Plane ◽  
Wide Range ◽  
The Difference

Austenitic stainless steel (SUS316L) was used as specimen material, and the plate specimens were deformed plastically with a wide range of strain rates (6.67×10-5~ 6.70×102/s). The residual micro-stress for each lattice plane was measured with hard synchrotron X-rays. The residual macro-stress due to tensile deformation depended on strain rate. The residual micro-stresses varied from tension to compression, depending on the diffraction elastic constant. The soft lattice plane had tensile residual stress, and the hard lattice plane had compressive residual stress. The higher the strain rate, the smaller the difference in residual micro-stresses. The residual micro-stresses of the surfaces peened with the laser-peening or water-jet-peening were examined. Both surfaces had exhibited large compressive residual stress. The residual micro-stress on the peened surfaces showed a tendency opposite to residual micro-stress due to tensile deformation.

scholarly journals Peening Natural Aging of Aluminum Alloy by Ultra-High-Temperature and High-Pressure Cavitation

2021 ◽  
Vol 11 (7) ◽  
pp. 2894
Author(s):  
Toshihiko Yoshimura ◽  
Masayoshi Iwamoto ◽  
Takayuki Ogi ◽  
Fumihiro Kato ◽  
Masataka Ijiri ◽  
...  
Keyword(s):  
Residual Stress ◽  
High Pressure ◽  
Aluminum Alloy ◽  
High Temperature ◽  
Compressive Residual Stress ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Natural Aging ◽  
Aging Treatment ◽  
Ultra High Temperature

The peening solution treatment was performed on AC4CH aluminum alloy by ultra-high-temperature and high-pressure cavitation (UTPC) processing, and the peening natural aging was examined. Furthermore, peening artificial aging treatment by low-temperature and low-pressure cavitation (LTPC) was performed, and the time course of peening natural aging and peening artificial aging were compared and investigated. It was found that when the AC4CH alloy is processed for an appropriate time by UTPC processing, compressive residual stress is applied and natural aging occurs. In addition, the UTPC processing conditions for peening natural aging treatment with high compressive residual stress and surface hardness were clarified. After peening artificial aging by LTPC processing, the compressive residual stress decreases slightly over time, but the compression residual stress becomes constant by peening natural aging through UTPC treatment. In contrast, it was found that neither natural nor artificial peening natural aging occurs after processing for a short time.

The Effects of Ultrasonic Nanocrystal Surface Modification Technique Temperature on Microstructure and Wear of Alloy 600

2016 ◽  
Vol 879 ◽  
pp. 926-931
Author(s):  
Jun Hyong Kim ◽  
Auezhan Amanov ◽  
Young Sik Pyun
Keyword(s):  
Residual Stress ◽  
Corrosion Resistance ◽  
Surface Modification ◽  
High Temperature ◽  
Compressive Residual Stress ◽  
Wear Behavior ◽  
Treatment Temperature ◽  
Alloy 600 ◽  
Term Operation ◽  
Superior Corrosion Resistance

Alloy 600 (UNS N06600) is an austenitic nickel-based alloy with superior corrosion resistance and high-temperature endurance, which determines its widespread applications in aeronautical, aerospace, marine and nuclear industries. Particularly, a number of nuclear components used Alloy 600 as their structure materials due to their high corrosion resistance, high-temperature endurance and excellent fabricant characteristics. Many failures have occurred in Alloy 600 with various forms of environmental degradations during long-term operation. In this study, an ultrasonic nanocrystal surface modification (UNSM) technique was applied to Alloy 600 at a room and a high temperature of 500 OC. The effects of UNSM treatment temperature on the microstructure and wear behavior including a compressive residual stress were investigated. The hardness, compressive residual stress with respect to depth from the top surface were measured. Also, the wear behavior of UNSM-treated at a room and a high temperature Alloy 600 specimen was compared to that of the untreated specimen. The increase in wear resistance by UNSM technique was discussed in terms of increased hardness, refined grain size and induced compressive residual stress.

Nondestructive Evaluation and Fracture Mechanism of Smart Material

2004 ◽  
Vol 261-263 ◽  
pp. 1379-1384 ◽  
Author(s):  
Jin Kyung Lee ◽  
Young Chul Park ◽  
Joon Hyun Lee ◽  
Sang Ll Lee ◽  
Kwan Do Hur
Keyword(s):  
Residual Stress ◽  
Shape Memory ◽  
Compressive Residual Stress ◽  
Processing Condition ◽  
Tensile Residual Stress ◽  
Tini Alloy ◽  
Matrix Composites ◽  
Pressing Method ◽  
The Matrix ◽  
The Difference

Tensile residual stress occurring due to the difference of coefficients of thermal expansion between fiber and matrix is one of the serious problems in metal matrix composites (MMC). In this study, TiNi alloy fiber was used to solve the problem of the tensile residual stress of TiNi/Al6061 shape memory alloy(SMA) composite as the reinforced material. TiNi alloy fiber improves the tensile strength of a composite by inducing compressive residual stress in the matrix using its shape memory effect. The fixture was made to hold TiNi shape memory fiber uniformly. Some tensile test specimens with several volume fractions are made by the hot pressing method under the optimum processing condition. In order to generate the compressive residual stress in TiNi/Al6061 SMA composite, 1%, 3% and 5% pre-strain was added in advance. It was evaluated the effect of compressive residual stress corresponding to pre-strains variation using the acoustic emission(AE) technique. AE technique was also used to clarify the damage behavior and the microscopic failure mechanism of TiNi/Al6061 SMA composite. In addition, a two-dimensional AE source location technique was applied to measure the position of the crack initiation and propagation in composites.

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.

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