scholarly journals Effects of temperature and load during hot impression behavior of Cr-Ni stainless steel

10.30544/745 ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 531-539
Author(s):  
P. Bharath Sreevatsava ◽  
E. Vara Prasad ◽  
A. Sai Deepak Kumar ◽  
Mohammad Fayaz Anwar ◽  
Vadapally Rama Rao ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Creep Rate ◽  
High Temperatures ◽  
Stainless Steels ◽  
Indentation Depth ◽  
Austenitic Stainless Steels ◽  
Primary Creep ◽  
Secondary Creep ◽  
Aqueous Corrosion ◽  
Creep Region

Austenitic Stainless steels are majorly used because of their high resistance to aqueous corrosion and high temperature properties. Some major applications of stainless steels at high temperatures include engine and exhaust components in aircrafts, recuperators in steel mills, and pulverized coal injection lances for blast furnaces. In all the above said applications, the components are constantly subjected to loads and high temperatures. This makes the study of their creep behavior very important to decide the life of the component. Cr-Ni stainless steel was used as a starting material, and hot impression creep test was performed on cylindrical samples of 10 mm height and 15 mm diameter for a dwell time of 150 min at two different loads of 84 and 98 MPa and at two different temperatures 450 and 500 °C. The time vs. indentation depth was plotted, and creep rate was calculated in each case. It was observed that with an increase in time, creep rate increased in the primary creep region and remained almost constant in the secondary creep region irrespective of temperature and load. The indentation depth and creep rate increased with an increase in load and temperature.

ALZ 316

Alloy Digest ◽  
1999 ◽  
Vol 48 (8) ◽  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Physical Properties ◽  
Tensile Properties ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Heat Treating

Abstract ALZ 316 is an austenitic stainless steel with good formability, corrosion resistance, toughness, and mechanical properties. It is the basic grade of the stainless steels, containing 2 to 3% molybdenum. After the 304 series, the molybdenum-containing stainless steels are the most widely used austenitic stainless steels. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-756. Producer or source: ALZ nv.

ALLOY 0Cr25Ni6Mo3CuN

Alloy Digest ◽  
1998 ◽  
Vol 47 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Temperature Performance ◽  
Steel Research ◽  
Oil Refinement

Abstract ALLOY 0Cr25Ni6Mo3CuN is one of four grades of duplex stainless steel that were developed and have found wide applications in China since 1980. In oil refinement and the petrochemical processing industries, they have substituted for austenitic stainless steels in many types of equipment, valves, and pump parts. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance, and corrosion resistance as well as forming and joining. Filing Code: SS-706. Producer or source: Central Iron & Steel Research Institute.

CARTECH 347

Alloy Digest ◽  
2021 ◽  
Vol 70 (9) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Stainless Steels ◽  
Intergranular Corrosion ◽  
Austenitic Stainless Steels ◽  
Heat Treating ◽  
Intermittent Heating ◽  
Technology Corporation ◽  
Carpenter Technology Corporation

Abstract CarTech 347 is a niobium+tantalum stabilized austenitic stainless steel. Like Type 321 austenitic stainless steel, it has superior intergranular corrosion resistance as compared to typical 18-8 austenitic stainless steels. Since niobium and tantalum have stronger affinity for carbon than chromium, carbides of those elements tend to precipitate randomly within the grains instead of forming continuous patterns at the grain boundaries. CarTech 347 should be considered for applications requiring intermittent heating between 425 and 900 °C (800 and 1650 °F). This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1339. Producer or source: Carpenter Technology Corporation.

scholarly journals Surface Modification of a Nickel-Free Austenitic Stainless Steel by Low-Temperature Nitriding

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1845
Author(s):  
Francesca Borgioli ◽  
Emanuele Galvanetto ◽  
Tiberio Bacci
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Stainless Steels ◽  
Volume Fraction ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Surface Layers ◽  
Modified Surface

Low-temperature nitriding allows to improve surface hardening of austenitic stainless steels, maintaining or even increasing their corrosion resistance. The treatment conditions to be used in order to avoid the precipitation of large amounts of nitrides are strictly related to alloy composition. When nickel is substituted by manganese as an austenite forming element, the production of nitride-free modified surface layers becomes a challenge, since manganese is a nitride forming element while nickel is not. In this study, the effects of nitriding conditions on the characteristics of the modified surface layers obtained on an austenitic stainless steel having a high manganese content and a negligible nickel one, a so-called nickel-free austenitic stainless steel, were investigated. Microstructure, phase composition, surface microhardness, and corrosion behavior in 5% NaCl were evaluated. The obtained results suggest that the precipitation of a large volume fraction of nitrides can be avoided using treatment temperatures lower than those usually employed for nickel-containing austenitic stainless steels. Nitriding at 360 and 380 °C for duration up to 5 h allows to produce modified surface layers, consisting mainly of the so-called expanded austenite or gN, which increase surface hardness in comparison with the untreated steel. Using selected conditions, corrosion resistance can also be significantly improved.

Developing New Cast Austenitic Stainless Steels With Improved High-Temperature Creep Resistance

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Philip J. Maziasz ◽  
John P. Shingledecker ◽  
Neal D. Evans ◽  
Michael J. Pollard
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Creep Strength ◽  
Stainless Steels ◽  
Creep Resistance ◽  
Austenitic Stainless Steels ◽  
Creep Rupture ◽  
Particulate Filter ◽  
Alloy Development ◽  
Wide Range

Oak Ridge National Laboratory and Caterpillar (CAT) have recently developed a new cast austenitic stainless steel, CF8C-Plus, for a wide range of high-temperature applications, including diesel exhaust components and turbine casings. The creep-rupture life of the new CF8C-Plus is over ten times greater than that of the standard cast CF8C stainless steel, and the creep-rupture strength is about 50–70% greater. Another variant, CF8C-Plus Cu/W, has been developed with even more creep strength at 750–850°C. The creep strength of these new cast austenitic stainless steels is close to that of wrought Ni-based superalloys such as 617. CF8C-Plus steel was developed in about 1.5 years using an “engineered microstructure” alloy development approach, which produces creep resistance based on the formation of stable nanocarbides (NbC), and resistance to the formation of deleterious intermetallics (sigma, Laves) during aging or service. The first commercial trial heats (227.5 kg or 500 lb) of CF8C-Plus steel were produced in 2002, and to date, over 27,215 kg (300 tons) have been produced, including various commercial component trials, but mainly for the commercial production of the Caterpillar regeneration system (CRS). The CRS application is a burner housing for the on-highway heavy-duty diesel engines that begins the process to burn-off particulates trapped in the ceramic diesel particulate filter (DPF). The CRS/DPF technology was required to meet the new more stringent emissions regulations in January, 2007, and subjects the CRS to frequent and severe thermal cycling. To date, all CF8C-Plus steel CRS units have performed successfully. The status of testing for other commercial applications of CF8C-Plus steel is also summarized.

Corrosion Resistance of Nickel-Free Austenitic Stainless Steels and their Nanocomposites with Hydroxyapatite in Ringer's Solution

2011 ◽  
Vol 674 ◽  
pp. 159-163 ◽  
Author(s):  
Maciej Tulinski ◽  
Mieczyslaw Jurczyk
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Mechanical Alloying ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Orthopedic Implants ◽  
Corrosion Current ◽  
Similar Process ◽  
Distinct Advantage ◽  
Ion Release

In this work Ni-free austenitic stainless steels with nanostructure and their nanocomposites were synthesized by mechanical alloying (MA), heat treatment and nitriding of elemental microcrystalline Fe, Cr, Mn and Mo powders with addition of hydroxyapatite (HA). Microhardness and corrosion tests' results of obtained materials are presented. Mechanical alloying and nitriding are very effective technologies to improve the corrosion resistance of stainless steel. Decreasing the corrosion current density is a distinct advantage for prevention of ion release and it leads to better cytocompatibility. Similar process in case of nanocomposites of stainless steel with hydroxyapatite helps achieve even better mechanical properties and corrosion resistance. Hence nanocrystalline nickel-free stainless steels and nickel-free stainless steel/hydroxyapatite nanocomposites could be promising bionanomaterials for use as a hard tissue replacement implants, e.g. orthopedic implants.

Producing HP Pump Barrels Utilizing Powder Metallurgy and Hot Isostatic Pressing

2009 ◽  
Author(s):  
Martin Bjurstro¨m ◽  
Carl-Gustaf Hjorth
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Hot Isostatic Pressing ◽  
Austenitic Stainless Steels ◽  
Pressure Vessels ◽  
Uniform Structure ◽  
Isostatic Pressing ◽  
Near Net Shape ◽  
Hip Process

The fabrication of near net shape powder metal (PM) components by hot isostatic pressing (HIP) has been an important manufacturing technology for steel and stainless steel alloys since about 1985. The manufacturing process involves inert gas atomization of powder, 3D CAD capsule design, sheet metal capsule fabrication and densification by HIP in very large pressure vessels. Since 1985, several thousand tonnes of parts have been produced. The major applications are found in the oil and gas industry especially in offshore applications, the industrial power generation industry, and traditional engineering industries. Typically, the components replace castings, forgings and fabricated parts and are produced in high alloy grades such as martensitic steels, austenitic stainless steels, duplex (ferritic/austenitic) stainless steels and nickel based superalloys. The application of PM/HIP near net shapes to pump barrels for medium to high pressure use has a number of advantages compared to the traditional forging and welding approach. First, the need for machining of the components is reduced to a minimum and welding during final assembly is reduced substantially. Mechanical properties of the PM/HIP parts are isotropic and equal to the best forged properties in the flow direction. This derives from the fine microstructure using powder powder and the uniform structure from the HIP process. Furthermore, when using the PM HIP process the parts are produced near net shape with supports, nozzles and flanges integrated. This significantly reduces manufacturing lead-time and gives greater design flexibility which improves cost for the final component. The PM HIP near net shape route has received approval from ASTM, NACE and API for specific steel, stainless steel and nickel base alloys. This paper reviews the manufacturing sequence for PM near net shapes and discusses the details of several successful applications. The application of the PM/HIP process to high pressure pump barrels is highlighted.

Study on the Effects of Heat Treatments on the Physical and Mechanical Characteristics of 1.4301 Stainless Steel

2021 ◽  
Vol 42 ◽  
pp. 57-62
Author(s):  
Maria Stoicănescu
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Mechanical Characteristics ◽  
Austenitic Stainless Steels ◽  
Heat Treatments ◽  
Hot Plastic Deformation ◽  
Improved Characteristics ◽  
Physical And Mechanical Characteristics

The 1.4301 stainless steel is part of the category of austenitic stainless steels, steels which do no undergo heat treatments in general, as they are intended for hot plastic deformation in particular. The aim of the research presented in this paper was to obtain significantly improved characteristics of the resistance properties in relation to the values obtained under classical conditions, by applying heat treatments. Samples taken from the delivery state material underwent annealing, quenching and ageing heat treatments. Subsequently, the samples thus treated were subjected to tests enabling the determination of the correlations between the heat treatment parameters, the structure and the properties.

Producing HP Pump Barrels Utilizing Powder Metallurgy and Hot Isostatic Pressing

2009 ◽  
Author(s):  
Martin Bjurstro¨m ◽  
Carl-Gustaf Hjorth
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Hot Isostatic Pressing ◽  
Austenitic Stainless Steels ◽  
Pressure Vessels ◽  
Uniform Structure ◽  
Isostatic Pressing ◽  
Near Net Shape ◽  
Hip Process

The fabrication of near net shape powder metal (PM) components by hot isostatic pressing (HIP) has been an important manufacturing technology for steel and stainless steel alloys since about 1985. The manufacturing process involves inert gas atomization of powder, 3D CAD capsule design, sheet metal capsule fabrication and densification by HIP in very large pressure vessels. Since 1985, several thousand tonnes of parts have been produced. The major applications are found in the oil and gas industry especially in offshore applications, the industrial power generation industry, and traditional engineering industries. Typically, the components replace castings, forgings and fabricated parts and are produced in high alloy grades such as martensitic steels, austenitic stainless steels, duplex (ferritic/austenitic) stainless steels and nickel based superalloys. The application of PM/HIP near net shapes to pump barrels for medium to high pressure use has a number of advantages compared to the traditional forging and welding approach. First, the need for machining of the components is reduced to a minimum and welding during final assembly is reduced substantially. Mechanical properties of the PM/HIP parts are isotropic and equal to the best forged properties in the flow direction. This derives from the fine microstructure using powder powder and the uniform structure from the HIP process. Furthermore, when using the PM HIP process the parts are produced near net shape with supports, nozzles and flanges integrated. This significantly reduces manufacturing lead-time and gives greater design flexibility which improves cost for the final component. The PM HIP near net shape route has received approval from ASTM, NACE and API for specific steel, stainless steel and nickel base alloys. This paper reviews the manufacturing sequence for PM near net shapes and discusses the details of several successful applications. The application of the PM/HIP process to high pressure pump barrels is highlighted.

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.

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