scholarly journals Effects of High Temperature Aging Treatment on the Microstructure and Impact Toughness of Z2CND18-12N Austenitic Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1691
Author(s):  
Hui Zhang ◽  
Yanfeng Liu ◽  
Xian Zhai ◽  
Wenkai Xiao
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Charpy Impact ◽  
Aging Treatment ◽  
Fracture Morphology ◽  
Charpy Impact Test ◽  
Scattered Electron ◽  
Σ Phase ◽  
Effects Of Aging

During the casting cooling process or the forging process, austenitic stainless steel will remain at around 800 °C for some time. During this period, precipitate particle behaviors in austenitic stainless steel (containing ferrite) will cause a reduction in ductility, which can lead to material cracking. In this study, the effects of aging at 800 °C on the microstructure, impact toughness and microhardness of Z2CND18-12N austenitic stainless steel were systematically investigated. The precipitation processes of the χ and σ phases were characterized by color metallography and back scattered electron (BSE) signals. The toughness was investigated by the Charpy impact test. After the aging treatment, the χ and σ phases precipitated successively in the ferrite, and as the aging duration increased, the χ-phase dissolved and the σ-phase precipitated along the austenite grain boundaries. These all lead to a decrease in toughness and an increase in microhardness. Finally, the relationship between fracture morphology and aging time is discussed herein, and a crack mechanism is given.

Effect of Aging Temperature on Fracture Toughness of Cast Austenitic Stainless Steel

2015 ◽  
Author(s):  
Yasufumi Miura ◽  
Masato Yamamoto
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Aging Temperature ◽  
Charpy Impact ◽  
Hardness Test ◽  
Charpy Impact Test ◽  
Test Material ◽  
Indentation Hardness ◽  
Fracture Toughness Test

In this study, fracture toughness of cast austenitic stainless steel aged at 300–450°C for up to 15000 h were investigated using fracture toughness test, Charpy impact test and indentation hardness test. Test material was statically casted grade CF-3M stainless steel. As a result of the tests, it was found that the fracture toughness and the Charpy absorbed energy tended to decrease with the increase of aging time. However, the behavior of thermal embrittlement varied at each aging temperature. In particular, the fracture toughness of the specimens aged at 300°C was almost the same as that of the unaged specimens. At elevated temperature, the differences of the fracture toughness between unaged specimens and aged specimens were smaller than that of tested at room temperature.

Effects of Aging Precipitates on the Mechanical and Corrosion Resistance Properties of 18Cr-18Mn-2Mo-0.96N Super High Nitrogen Austenitic Stainless Steel

2013 ◽  
Vol 395-396 ◽  
pp. 284-288 ◽  
Author(s):  
Zu Rui Zhang ◽  
Zhen Ye Zhao ◽  
Chun Zhi Li ◽  
Zhou Hua Jiang ◽  
Hua Bing Li
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Aging Time ◽  
Volume Fraction ◽  
Charpy Impact ◽  
Optical Microscope ◽  
High Nitrogen ◽  
Effects Of Aging ◽  
The Impact

This paper investigates the effects of aging precipitates on the mechanical and corrosion resistance properties of 18Cr-18Mn-2Mo-0.96N super high nitrogen austenitic stainless steel (HNS) through Vickers hardness, Charpy impact, tensile and electrical chemical methods. The probable affected mechanism is discussed by optical microscope (OM) and transmission electron microscopy (TEM). The results are presented as follow: the initial TTP curve with 0.05% precipitates volume fraction presents C type which has a nose temperature at 850°C with an incubation period for 60s. The precipitates increase with prolonging aging time to 40%. The HV results of aged HNS present firstly decrease then increase, the relevant yield strength firstly increase then decrease with increasing the aging time. Meanwhile, the impact energy, ultimate tensile strength and elongation are deteriorated significantly because of the formation and growth of cellular Cr2N and χ phase with concomitant increased amount of intergranular Cr2N. The IGC susceptibility increases and the pitting corrosion potentials decrease because of the Cr, N and Mo depletion through the formation of intergranular, cellular Cr2N and intermetallic χ precipitates by aging treatments.

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.

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

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

Zinc diffusion induced precipitation of σ-phase in austenitic stainless steel

2019 ◽  
Vol 116 (6) ◽  
pp. 618
Author(s):  
Nega Setargew ◽  
Daniel J. Parker
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Stainless Steels ◽  
Intermetallic Phase ◽  
Austenitic Stainless Steels ◽  
Austenite Matrix ◽  
Σ Phase ◽  
Intermediate Phases ◽  
Zinc Diffusion

Zinc diffusion-induced degradation of AISI 316LN austenitic stainless steel pot equipment used in 55%Al-Zn and Zn-Al-Mg coating metal baths is described. SEM/EDS analyses results showed that the diffused zinc reacts with nickel from the austenite matrix and results in the formation of Ni-Zn intermetallic compounds. The Ni-Zn intermetallic phase and the nickel depleted zones form a periodic and alternating layered structure and a mechanism for its formation is proposed. The role of cavities and interconnected porosity in zinc vapour diffusion-induced degradation and formation of Ni-Zn intermediate phases is also discussed. The formation of Ni-Zn intermediate phases and the depletion of nickel in the austenite matrix results in the precipitation of σ-phase and α-ferrite in the nickel depleted regions of the matrix. This reaction will lead to increased susceptibility to intergranular cracking and accelerated corrosion of immersed pot equipment in the coating bath. Zinc diffusion induced precipitation of σ-phase in austenitic stainless steels that we are reporting in this work is a new insight with important implications for the performance of austenitic stainless steels in zinc containing metal coating baths and other process industries. This new insight will further lead to improved understanding of the role of substitutional diffusion and the redistribution of alloying elements in the precipitation of σ-phase in austenitic stainless steels.

EFFECT OF BORON ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF HOT-ROLLED Nb-ADDED HSLA H-SECTION STEEL

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1885-1890 ◽  
Author(s):  
ZUOCHENG WANG ◽  
GUOTAO CUI ◽  
TAO SUN ◽  
WEIMIN GUO ◽  
XIULING ZHAO ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Charpy Impact ◽  
High Strength ◽  
Charpy Impact Test ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Boron Addition ◽  
Low Temperature Impact Toughness ◽  
The Impact

In our research, boron was added into the Nb -added high strength low alloy (HSLA) H -section steels. The contents of boron added were 4ppm, 8ppm and 11ppm, respectively. The mechanical properties of H -section steels with/without boron were examined by using uniaxial tensile test and Charpy impact test ( V -notch). The morphologies of the microstructure and the fracture surfaces of the impact specimens were observed by metalloscope, stereomicroscope and electron probe. The experimental results indicate that boron gives a significant increase in impact toughness, especially in low temperature impact toughness, though it leads to an unremarkable increase in strength and plasticity. For instance, the absorbed energy at -40°C reaches up to 126J from 15J by 8ppm boron addition, and the ductile-brittle transition temperature declines by 20°C. It is shown that boron has a beneficial effect on grain refinement. The fracture mechanism is transited from cleavage fracture to dimple fracture due to boron addition.

Effect of Shock Temperature on the Impact Toughness of Butt-Joint

2012 ◽  
Vol 602-604 ◽  
pp. 2096-2099
Author(s):  
Min You ◽  
Ling Wu ◽  
Hai Zhou Yu ◽  
Jing Rong Hu ◽  
Mei Li
Keyword(s):  
Impact Toughness ◽  
Impact Test ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Butt Joint ◽  
Adhesively Bonded ◽  
A Value ◽  
Shock Temperature ◽  
Izod Impact ◽  
The Impact

The effect of the shock temperature and time on the impact toughness of the adhesively bonded steel butt joint under Charpy or Izod impact test is studied using the experimental method. The results obtained show that the impact toughness decreases when the shock temperature increased. When the curing time, temperature as well as the open assembly time was set as constant, the higher the shock temperature is, the lower the impact toughness of the joint. Comparing to the Charpy impact test, the Izod impact test is more sensitive to the shock temperature. When the shock temperature is set at a value not less than 300 C, the impact toughness measured is nearly the same as zero due to decomposition, carbonization and volatilization of the adhesive.

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