The effect of neutron irradiation on the impact toughness of austenitic stainless steel in ultrafine-grained state

2021 ◽  
Vol 544 ◽  
pp. 152680
Author(s):  
Valentin K. Shamardin ◽  
Tatyana M. Bulanova ◽  
Alexander E. Fedoseev ◽  
Alexei A. Karsakov ◽  
Ruslan Z. Valiev ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Neutron Irradiation ◽  
Ultrafine Grained ◽  
The Impact

scholarly journals Evaluation of Microstructure and Impact Toughness of Shielded Metal Arc Dissimilar Weldments of High Strength Low Alloy Steel and Austenitic Stainless Steel

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Misbahu A Hayatu ◽  
Emmanuel T Dauda ◽  
Ola Aponbiede ◽  
Kamilu A Bello ◽  
Umma Abdullahi
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Impact Energy ◽  
High Strength ◽  
Impact Testing ◽  
Welding Parameters ◽  
Dissimilar Weld ◽  
Weld Joints ◽  
The Impact

There is a growing interest for novel materials of dissimilar metals due to higher requirements needed for some critical engineering applications. In this research, different dissimilar weld joints of high strength low alloy (HSLA) and 316 austenitic stainless steel grades were successfully produced using shielded metal arc welding (SMAW) process with 316L-16 and E7018 electrodes. Five variations of welding currents were employed within the specified range of each electrode. Other welding parameters such as heat inputs, welding speeds, weld sizes, arc voltages and time of welding were also varied. Specimens for different weld joint samples were subjected to microstructural studies using optical and scanning electron microscopes. The impact toughness test was also conducted on the samples using Izod impact testing machine. The analysis of the weld microstructures indicated the presence of type A and AF solidification patterns of austenitic stainless steels. The results further showed that the weld joints consolidated with E7018 electrode presented comparatively superior impact energy to the weldments fabricated by 316L-16 electrode. The optimum impact energy of E7018-weld joints (51J) was attained at higher welding heat inputs while that of 316L-16-weld joints (35J) was achieved at lower welding heat inputs, which are necessary requirements for the two electrodes used in the experiment. Hence, the dissimilar weld joints investigated could meet requirement for engineering application in offshore and other critical environments.Keywords—Dissimilar metal weld, heat input, impact toughness, microstructures

Cyclic Crack Growth Rate of Irradiated Austenitic Stainless Steel Welds in Simulated BWR Environment

2011 ◽  
Author(s):  
Y. Chen ◽  
B. Alexandreanu ◽  
W. J. Shack ◽  
K. Natesan ◽  
A. S. Rao
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Crack Growth ◽  
Neutron Irradiation ◽  
Growth Rates ◽  
Reactor Core ◽  
Cracking Behavior ◽  
Steel Welds ◽  
The Impact ◽  
Crack Growth Rates

Reactor core internal components in light water reactors are subjected to neutron irradiation. It has been shown that the austenitic stainless steels used in reactor core internals are susceptible to stress corrosion cracking after extended neutron exposure. This form of material degradation is a complex phenomenon that involves concomitant conditions of irradiation, stress, and corrosion. Interacting with fatigue damage, irradiation-enhanced environmental effects could also contribute to cyclic crack growth. In this paper, the effects of neutron irradiation on cyclic cracking behavior were investigated for austenitic stainless steel welds. Post-irradiation cracking growth tests were performed on weld heat-affected zone specimens in a simulated boiling water reactor environment, and cyclic crack growth rates were obtained at two doses. Environmentally enhanced cracking was readily established in irradiated specimens. Crack growth rates of irradiated specimens were significantly higher than those of nonirradiated specimens. The impact of neutron irradiation on environmentally enhanced cyclic cracking behavior is discussed for different load ratios.

Effect of Static Aging on Mechanical Properties of an 18Cr-8Ni-W-Nb-V-N Stainless Steel

2012 ◽  
Vol 706-709 ◽  
pp. 2211-2216
Author(s):  
Ilya Nikulin ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Early Stage ◽  
Secondary Phase ◽  
Fracture Mechanisms ◽  
Aged Condition ◽  
The Impact

The interrelations between microstructure, precipitation and mechanical properties of the 18Cr-8Ni-W-Nb-V-N austenitic stainless steel were examined under long-term aging at 650°C. It was shown that aging leads to decreasing strength characteristics with increasing aging time despite the fact that hardness tends to increase. In none-aged condition the present steel exhibits superior impact toughness of about 255 J/cm-2. This values decreases gradually at the early stage of the aging. After 1000 hours exposure the impact toughness is 195 J/cm-2 and decreases sharply to 135 J/cm-2 at 3000 hours. However, an evidence for ductile fracture was found even after long-term aging. Degradation in impact toughness and mechanical properties with aging is discussed in relation to microstructure evolution, precipitations of the secondary phase and fracture mechanisms.

Tensile properties of shielded metal arc welded dissimilar joints of nuclear grade ferritic steel and austenitic stainless steel

2016 ◽  
Vol 25 (5-6) ◽  
pp. 171-178
Author(s):  
K. Karthick ◽  
S. Malarvizhi ◽  
V. Balasubramanian ◽  
S.A. Krishnan ◽  
G. Sasikala ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Tensile Properties ◽  
Ferritic Steel ◽  
Power Plants ◽  
Dissimilar Joint ◽  
Dissimilar Joints ◽  
Transverse Tensile ◽  
The Impact

AbstractIn nuclear power plants, modified 9Cr-1Mo ferritic steel (Grade 91 or P91) is used for constructing steam generators (SG’s) whereas austenitic stainless steel (AISI 316LN) is a major structural member for intermediate heat exchanger (IHX). Therefore, a dissimilar joint between these materials is unavoidable. In this investigation, dissimilar joints were fabricated by Shielded Metal Arc Welding (SMAW) process with Inconel 82/182 filler metals. Transverse tensile properties and Charpy V-notch impact toughness for different regions of dissimilar joints of modified 9Cr-1Mo ferritic steel and AISI 316LN austenitic stainless steel were evaluated as per the standards. Microhardness distribution across the dissimilar joint was recorded. Microstructural features of different regions were characterized by optical and scanning electron microscopy. The transverse tensile properties of the joint is found to be inferior to base metals. Impact toughness values of different regions of dissimilar metal weld joint (DMWJ) is slightly higher than the prescribed value. Formation of a soft zone at the outer edge of the HAZ will reduce the tensile properties of DMWJ. The complex microstructure developed at the interfaces of DMWJ will reduce the impact toughness values.

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.

Favorable Modulation of Pre-Osteoblast Response to Nanograined/Ultrafine-grained Structures in Austenitic Stainless Steel

2009 ◽  
Vol 21 (12) ◽  
pp. 1280-1285 ◽  
Author(s):  
R.D.K. Misra ◽  
W-W. Thein-Han ◽  
T.C. Pesacreta ◽  
K.H. Hasenstein ◽  
M.C. Somani ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ultrafine Grained

Investigation on Impact Energy of S30403 Austenitic Stainless Steel at Different Temperatures

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Zhiwei Chen ◽  
Caifu Qian ◽  
Guoyi Yang ◽  
Xiang Li
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cross Section ◽  
Test Temperature ◽  
Impact Energy ◽  
Welded Joint ◽  
Charpy Impact ◽  
Base Plate ◽  
Charpy Impact Energy ◽  
The Impact

In this paper, a series of impact tests on S30403 austenitic stainless steel at 20/−196/−269 °C were performed to determine the effects of cryogenic temperatures on the material properties. Both base plate and welded joint including weld and heat-affected zone were tested to obtain the Charpy impact energy KV2 and lateral expansion rate at the cross section. It was found that when the test temperature decreased from 20 °C to −196 °C or −269 °C, both the Charpy impact energy KV2 at the base plate and welded joint decreased drastically. Specifically, the impact energy KV2 decreased by 20% at the base plate and decreased by 54% at the welded joint from 20 °C to −196 °C, but the impact energy of base plate and welded joint did not decrease, even increased when test temperature decreased from −196 °C to −269 °C. Either at 20 °C or −196 °C, the impact energy KV2 with 5 × 10 × 55 mm3 specimens was about 0.53 times that of the 7.5 × 10 × 55 mm3 specimens, much lower than 2/3, the ratio of two specimens’ cross section areas.

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