scholarly journals The Effects of Long-Term Operation and High Temperature on Material Properties of Austenitic Stainless Steel Type 321H

2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Ahmed Naif Al-Khazraji ◽  
Samir Ali Amin ◽  
Husam Ahmed Al-Warmizyari
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Yield Strength ◽  
Mechanical Testing ◽  
Tube Material ◽  
Absorbed Energy ◽  
Long Time

Changes in mechanical properties of material as a result of service in different conditions can be provided by mechanical testing to assist the estimation of current internal situation of these materials, or the degree of deterioration may exist in furnaces serviced at high temperature and exceed their design life. Because of the rarity works on austenitic stainless steel material type AISI 321H, in this work, ultimate tensile strength, yield strength, elongation, hardness, and absorbed energy by impact are evaluated based on experimental data obtained from mechanical testing. Samples of tubes are extracted from furnace belong to hydrotreaterunit, also samples from un-used tube material are used to make comparisons between these properties. Tensile properties of stainless steel (AISI 321H) were decreased as temperature increases; the trend of properties decreasing for the samples of un-used tube material is the same for the ex-used material. The trend of stress-strain curve will not change due to elevated temperature exposure for long time of service, except the yield strength will be higher in this diagram. The yield strength increased under these conditions, but the ability of material  which is elongated will decrease. Hardness and absorbed energy increased by 11.28 and 14% respectively when the material is aged for long time under effect of high temperature accompanied with creep effect. Keywords:  Hardness, Impact, Mechanical Properties, Stainless Steel 321H, Mechanical Properties, Tensile Strength, Tube Furnace.

Quantitative Analysis of Pre-Strain Effect on Mechanical Properties of the Austenitic Stainless Steel

2014 ◽  
Author(s):  
Zhiwei Chen ◽  
Caifu Qian ◽  
Guoyi Yang ◽  
Xiang Li
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Yield Strength ◽  
Tensile Testing ◽  
Control Mode ◽  
Strain Effect ◽  
Strain Control

The test of austenitic stainless steel specimens with strain control mode of pre-strain was carried out. The range of pre-strain is 4%, 5%, 6%, 7%, 8%, 9% and 10% on austenitic stainless steel specimens, then tensile testing of these samples was done and their mechanical properties after pre-strain were gotten. The results show that the pre-strain has little effect on tensile strength, and enhances the yield strength more obviously. According to the experimental data, we get a relational expression of S30408 between the value of yield strength and pre-strain. We can obtain several expressions about different kinds of austenitic stainless steel by this way. It is convenient for designers to get the yield strength of austenitic stainless steel after pre-strain by the value of pre-strain and the above expression.

Influence of Cold Rolling Reduction on Microstructure and Mechanical Properties in 204C2 Austenitic Stainless Steel

2019 ◽  
Vol 944 ◽  
pp. 193-198
Author(s):  
Tian Yi Wang ◽  
Ren Bo Song ◽  
Heng Jun Cai ◽  
Jian Wen ◽  
Yang Su
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Cold Rolling ◽  
Stainless Steels ◽  
Rolling Reduction ◽  
Cold Rolling Reduction

The present study investigated the effect of cold rolling reduction on microstructure and mechanical properties of a 204C2 Cr–Mn austenitic stainless steel which contained 16%Cr, 2%Ni, 9%Mn and 0.083 %C). The 204C2 austenitic stainless steels were cold rolled at multifarious thickness reductions of 10%, 20%, 30%,40% and 50%, which were compared with the solution-treated one. Microstructure of them was investigated by means of optical microscopy, X-ray diffraction technique and scanning electron microscopy. For mechanical properties investigations, hardness and tensile tests were carried out. Results shows that the cold rolling reduction induced the martensitic transformation (γ→α ́) in the structure of the austenitic stainless steel. With the increase of the rolling reduction, the amount of strain-induced martensite increased gradually. Hardness, ultimate tensile strength and yield strength increased with the incremental rolling reduction in 204C2 stainless steels, while the elongation decreased. At the thickness reduction of 50%, the specimen obtained best strength and hardness. Hardness of 204C2 stain steel reached 679HV. Ultimate tensile strength reached 1721 MPa. Yield strength reached 1496 MPa.

Evaluation and Characterization of ASS316L at Sub-Zero Temperature

2019 ◽  
Author(s):  
Satyanarayana Kosaraju ◽  
Anil Kalluri ◽  
Swadesh Kumar Singh ◽  
Ahsan ul Haq
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Strain Hardening ◽  
Process Parameters ◽  
Salt Water ◽  
Strain Hardening Exponent

Abstract Austenitic Stainless-Steel grade 316L is one among the significant ASS grades which is most commonly used in various industry sectors. It has excellent corrosion resistance in ordinary atmospheric and also in more arduous environments such as salt water and environments where resistance to chloride corrosion is required. Whilst performing well when exposed to relatively high temperatures, this grade of Austenitic Stainless steel also maintains its strength and toughness at sub-zero temperatures, making this an excellent choice for various applications in industries sectors such as Marine, general construction, and water treatment. Therefore, present study focused on evaluating the mechanical properties such as ultimate tensile strength (UTS), yield strength (YS) and strain hardening exponent (n) are evaluated based on the experimental data obtained from the uniaxial isothermal tensile tests performed at an interval of −25 °C from 0 °C to −50 °C and at three orientations (0, 45, 90) degrees to the rolling direction and cross head velocity (3, 5, 7) mm/min were chosen. A total of 27 experiments have been planned based on design of experiments to conduct experiments. A mathematical model for the prediction of ultimate tensile strength (UTS), yield strength (YS) and strain hardening exponent (n) was developed using process parameters such as temperature, orientation and cross head velocities. Results have shown that mechanical properties can be predicted with a reasonable accuracy within the range of process parameters considered in this study.

Microstructure Evolution and Property of Austenitic Stainless Steel after ECAP

2012 ◽  
Vol 268-270 ◽  
pp. 291-296
Author(s):  
Li Min Wang ◽  
Zhi Hua Gong ◽  
Gang Yang ◽  
Zheng Dong Liu ◽  
Han Sheng Bao
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Shear Stress ◽  
Austenitic Stainless Steel ◽  
Yield Strength ◽  
Microstructure Evolution ◽  
Ultrafine Grain ◽  
Angular Pressing

Ultrafine-grain or even nano-grain microstructure can be made by equal channel angular pressing (ECAP), mainly resulting from shear strain. The authors experimentally investigated 00Cr18Ni12 austenitic stainless steel and its mechanical properties during and after ECAP. The results showed that because of larger shear stress, many slipping bands occured inside grains, with the increase of pressing pass, the slipping bands may interact with each other to separate slipping bands into sub-grains, finally, the sub-grains transformed into new grains with large angular boundaries. The grain size was about 200nm after the 7th pass. After the 1st and 2nd pass, the tensile strength was higher 93% and 144% than that without ECAP, the yield strength was 5.3 and 6.6 times of that without ECAP respectively.

NIROSTA 4318

Alloy Digest ◽  
2003 ◽  
Vol 52 (5) ◽  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Physical Properties ◽  
Intergranular Corrosion ◽  
Heat Treating ◽  
Temperature Performance ◽  
Lower Carbon

Abstract NIROSTA 4318 is an austenitic stainless steel with good formability and with high mechanical properties due to the addition of nitrogen. The lower carbon content improves corrosion resistance when considering intergranular corrosion. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-883. Producer or source: ThyssenKrupp Nirosta GmbH.

High Temperature Performance of Cast CF8C-Plus Austenitic Stainless Steel

2010 ◽  
Author(s):  
Philip J. Maziasz ◽  
Bruce A. Pint
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Gas Turbines ◽  
National Laboratory ◽  
Austenitic Stainless Steels ◽  
Medium Size ◽  
Temperature Oxidation ◽  
Oak Ridge

Covers and casings of small to medium size gas turbines, can be made from cast austenitic stainless steels, including grades such as CF8C, CF3M, or CF10M. Oak Ridge National Laboratory (ORNL) and Caterpillar have developed a new cast austenitic stainless steel, CF8C-Plus, that is a fully-austenitic stainless steel, based on additions of Mn and N to the standard Nb-stabilized CF8C steel grade. The Mn addition improves castability, as well as increasing the alloy solubility for N, and both Mn and N act synergistically to boost mechanical properties. CF8C-Plus steel has outstanding creep-resistance at 600°–900°C, which compares well with Ni-based superalloys like alloys X, 625, 617 and 230. CF8C-Plus also has very good fatigue and thermal fatigue resistance. It is used in the as-cast condition, with no additional heat-treatments. While commercial success for CF8C-Plus has been mainly for diesel exhaust components, this steel can also be considered for gas-turbine and microturbine casings. The purpose of this paper is to demonstrate some of the mechanical properties and update the long-term creep-rupture data, and to present new data on the high-temperature oxidation behavior of these materials, particularly in the presence of water vapor.

Microstructure and Mechanical Properties of 45 Steel by Zero Time Holding Quenching

2011 ◽  
Vol 335-336 ◽  
pp. 577-582
Author(s):  
Xiao Wen Chen ◽  
De Fen Zhang ◽  
Guang Wen Long ◽  
Qin Zou ◽  
Li Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Temperature ◽  
Yield Strength ◽  
Quenching Temperature ◽  
Universal Testing ◽  
Quenching Condition ◽  
Steel Increase ◽  
Different Temperatures ◽  
Zero Time

45 steel was quenched with zero time holding at different temperatures, followed by a high temperature tempering. The influence of quenching temperature on hardness, yield strength, tensile strength and microstructure of the steels was investigated by Rockwell tester, universal testing machines and metallographic microscopy, respectively. The results show that under quenching condition of zero time holding, hardness and strength of the 45 steel increase with increasing quenching temperature and reach the maximum at 860 °C, where the content of martensite is maximum while that of ferrite is minimum in the specimen. At higher temperatures, the grains become obviously coarse, resulting in decrease of mechanical properties.

The Stress Corrosion Cracking of Austenitic Stainless Steel Heat Exchange Tubes: Three Cases Study

2010 ◽  
Author(s):  
Shugen Xu ◽  
Weiqiang Wang ◽  
Huadong Liu
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Austenitic Stainless Steel ◽  
Chloride Concentration ◽  
Tube Material ◽  
Steel Tubes ◽  
High Temperature Water ◽  
Temperature Water

In this paper, three leakage failure cases of heat exchange tubes have been introduced. The reasons of the leakage for austenitic stainless steel tubes and overlay welding layer on the tube sheet have been analyzed. Through the investigation of the operation process and histories of the equipment, and after chemical compositions analysis of tube material and corrosion products, metallographic test of specimens with cracks, and fracture surface scan with Scanning Electron Microscope (SEM), the cracking reason and mode are described as the Stress Corrosion Cracking (SCC) of austenitic stainless steel. This kind of cracking in three cases was induced by the micro chloride in the high temperature water (or steam). Moreover, sulfide and dissolved oxygen also reduced the threshold value of chloride concentration and enhanced the corrosion rate for SCC. The cracking mode of Case A and B are transgranular; and Case C is intergranular. It indicates that for this kind of in-service heat exchanger, the operators should not only control the chloride concentration in feed water, but also the sulfide and dissolved oxygen in the future. The austenitic stainless steel tubes (China steel types-1Cr18Ni9Ti and 0Cr18Ni10Ti, equal to Type 304 and Type 321 according to ASME code) used in this cases are not fit to this condition. Thus, for the new heat exchanger design, the tube material should be changed into austenitic-ferritic (duplex phase) steel, such as 2205 Series, which has an excellent performance for SCC resistance in the high temperature water (or steam) with chloride.

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