Probing deformation processes in near-defect free volume in high strength–high ductility nanograined/ultrafine-grained (NG/UFG) metastable austenitic stainless steels

2010 ◽  
Vol 63 (11) ◽  
pp. 1057-1060 ◽  
Author(s):  
R.D.K. Misra ◽  
Z. Zhang ◽  
Z. Jia ◽  
M.C. Somani ◽  
L.P. Karjalainen
Keyword(s):  
Free Volume ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
High Ductility ◽  
Ultrafine Grained ◽  
Deformation Processes

AVESTA SHEFFIELD SAF 2507

Alloy Digest ◽  
1996 ◽  
Vol 45 (9) ◽  
Keyword(s):  
High Resistance ◽  
Stainless Steels ◽  
Coefficient Of Thermal Expansion ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Heat Treating ◽  
General Corrosion ◽  
Temperature Performance ◽  
Chloride Stress Corrosion Cracking ◽  
Very High

Abstract Avesta Sheffield SAF 2507 is an austenitic/ferritic duplex stainless steel with very high strength. The alloy has a lower coefficient of thermal expansion and a higher thermal conductivity than austenitic stainless steels. The alloy has a high resistance to pitting, crevice, and general corrosion; it has a very high resistance to chloride stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-652. Producer or source: Avesta Sheffield Inc.

scholarly journals Effect of Neutron Irradiation on the Mechanical Properties, Swelling and Creep of Austenitic Stainless Steels

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2622
Author(s):  
Malcolm Griffiths
Keyword(s):  
Mechanical Properties ◽  
Stainless Steels ◽  
Dimensional Stability ◽  
Operating Experience ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Gas Production ◽  
Rate Theory ◽  
Fast Reactors ◽  
Internal Structures

Austenitic stainless steels are used for core internal structures in sodium-cooled fast reactors (SFRs) and light-water reactors (LWRs) because of their high strength and retained toughness after irradiation (up to 80 dpa in LWRs), unlike ferritic steels that are embrittled at low doses (<1 dpa). For fast reactors, operating temperatures vary from 400 to 550 °C for the internal structures and up to 650 °C for the fuel cladding. The internal structures of the LWRs operate at temperatures between approximately 270 and 320 °C although some parts can be hotter (more than 400 °C) because of localised nuclear heating. The ongoing operability relies on being able to understand and predict how the mechanical properties and dimensional stability change over extended periods of operation. Test reactor irradiations and power reactor operating experience over more than 50 years has resulted in the accumulation of a large amount of data from which one can assess the effects of irradiation on the properties of austenitic stainless steels. The effect of irradiation on the intrinsic mechanical properties (strength, ductility, toughness, etc.) and dimensional stability derived from in- and out-reactor (post-irradiation) measurements and tests will be described and discussed. The main observations will be assessed using radiation damage and gas production models. Rate theory models will be used to show how the microstructural changes during irradiation affect mechanical properties and dimensional stability.

scholarly journals Gradient twinned 304 stainless steels for high strength and high ductility

2016 ◽  
Vol 667 ◽  
pp. 179-188 ◽  
Author(s):  
Aiying Chen ◽  
Jiabin Liu ◽  
Hongtao Wang ◽  
Jian Lu ◽  
Y. Morris Wang
Keyword(s):  
Stainless Steels ◽  
High Strength ◽  
High Ductility

Application of Physical Simulation for Developing New Steel Types

2008 ◽  
Vol 575-578 ◽  
pp. 1002-1007 ◽  
Author(s):  
L. Pentti Karjalainen ◽  
Mahesh C. Somani ◽  
Atef S. Hamada
Keyword(s):  
Mechanical Properties ◽  
Stainless Steels ◽  
Physical Simulation ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Carbon Steels ◽  
Austenitic Steels ◽  
Low Carbon ◽  
Modelling Studies ◽  
Electron Microscopes

Processing of a large number of novel steel types, such as DP, TRIP, CP and TWIP, and high-strength low-carbon bainitic and martensitic DQ-T steels, have been developed based on physical simulation and modelling studies. Among stainless steels, guidelines for processing of ultra-fine grained austenitic stainless steels have been created. Physical simulation has been used by employing a Gleeble thermo-mechanical simulator to reveal the phenomena occurring in the hot rolling stage (the flow resistance, recrystallization kinetics and microstructure evolution), and in the cooling stage (CCT diagrams) for carbon steels and in short-term annealing of cold rolled metastable austenitic steels. Connecting these data with microstructures examined in optical and electron microscopes and resultant mechanical properties have improved the understanding on complex phenomena occurring in the processing of these steels and the role of numerous process variables in the optimization of enhanced mechanical properties.

Tailoring stacking fault energy for high ductility and high strength in ultrafine grained Cu and its alloy

2006 ◽  
Vol 89 (12) ◽  
pp. 121906 ◽  
Author(s):  
Y. H. Zhao ◽  
Y. T. Zhu ◽  
X. Z. Liao ◽  
Z. Horita ◽  
T. G. Langdon
Keyword(s):  
High Strength ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
High Ductility ◽  
Ultrafine Grained

SSRT and Fatigue Crack Growth Properties of High-Strength Austenitic Stainless Steels in High-Pressure Hydrogen Gas

2014 ◽  
Author(s):  
Hisatake Itoga ◽  
Takashi Matsuo ◽  
Akihiro Orita ◽  
Hisao Matsunaga ◽  
Saburo Matsuoka ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Hydrogen Gas ◽  
Internal Hydrogen ◽  
Acceleration Rate ◽  
Type 304

Slow strain rate tests (SSRTs) were performed with two types of high-strength austenitic stainless steels, Types AH and BX, as well as with two types of conventional austenitic stainless steels, Types 304 and 316L. The tests used the following combinations of specimen types and test atmospheres: (i) non-charged specimens tested in air, (ii) hydrogen-charged specimens tested in air (tests for internal hydrogen), and (iii) non-charged specimens tested in hydrogen gas at pressures of 78 ∼ 115 MPa (tests for external hydrogen). Type 304 exhibited a marked reduction of ductility in the tests for both internal hydrogen and external hydrogen, whereas Types AH, BX and 316L exhibited little or no degradation. In addition, fatigue crack growth (FCG) tests for the four types of steels were also carried out in air and hydrogen gas at pressures of 100 ∼ 115 MPa. In Type 304, FCG in hydrogen gas was more than 10 times as fast as that in air, whereas the acceleration rate remained within 1.5 ∼ 3 times in Types AH, BX and 316L. It was presumed that, in Types AH and BX, a small amount of additive elements, e.g. nitrogen and niobium, increased the strength as well as the stability of the austenitic phase, which thereby led to the excellent resistance against hydrogen.

scholarly journals Cutting Performance of Austenitic and Duplex Stainless Steels with Drills of Three Cutting Edges

2021 ◽  
Author(s):  
João Marouvo ◽  
Pedro Ferreira ◽  
Fernando Simões
Keyword(s):  
High Pressure ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Duplex Stainless Steels ◽  
Tool Geometry ◽  
Internal Cooling ◽  
Drilling Performance ◽  
External Cooling ◽  
Cutting Vibration

Austenitic and duplex stainless steels are considered be the best in corrosion resistance among different grades of stainless steels. Due to high strength, duplex stainless steels applications are increasingly as an alternative to the austenitic stainless steels. In this sense, the machining study of this materials is an important issue, in order to better understand the performance of the tools and the quality of the parts manufactured for high-demand industries. In this research, the machinability of both stainless steels was evaluated in the drilling operation, using drills with three cutting edges. This type of drill geometry is particularly useful when conventional solid carbide drills fail. The drill point of triple edge is very stable, demonstrating optimal positioning accuracy and better performance in deep bores. Using the same tool geometry, a comparative analysis of drilling performance on austenitic and duplex stainless steels was made. In experimental procedure, external low-pressure cooling or internal high-pressure cooling was applied alternatively. The cutting vibration, the tool wear, the roughness and the hole diameter accuracy were evaluated in the series of holes made. The obtained results show that the most important factor to increase the number of holes made is the use of high-pressure internal cooling. When external cooling is used, AISI 304 have a worse behaviour than duplex stainless steel, due to greater susceptibility to built-up-edge formation and work hardening. The tool deterioration is mainly non-uniform chipping for external cooling and flank wear for internal cooling.

Hydrogen-Assisted Fracture Mechanisms in Ultrafine-Grained CrNi Austenitic Stainless Steels with Different Initial Microstructures

2018 ◽  
Vol 941 ◽  
pp. 370-375
Author(s):  
Sergey Astafurov ◽  
Elena Astafurova ◽  
Valentina Moskvina ◽  
Galina G. Maier ◽  
Eugene Melnikov ◽  
...  
Keyword(s):  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Fracture Mechanisms ◽  
Flow Strength ◽  
Hydrogen Charging ◽  
Ultrafine Grained ◽  
Electrolytic Hydrogen ◽  
Cold Rolling And Annealing ◽  
Abc Pressing ◽  
Assisted Fracture

We investigated the effect of electrolytic hydrogen-charging on regularities of plastic flow, strength and fracture mechanisms of AISI 316L and 321 austenitic stainless steels. In the steels, an ultrafine-grained structure of various morphologies was formed using methods of warm abc-pressing and thermomechanical treatment (cold rolling and annealing). Hydrogen-charging of ultrafine-grained steels reduces their yield strength and elongation. The high dislocation density and low-angle boundaries inhibit the effects of hydrogen embrittlement in 316L and 321 steels.

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