Application of Thermo-Mechanical Process to Achieve Nanostructure in 301 Austenitic Stainless Steels

2011 ◽  
Vol 312-315 ◽  
pp. 51-55
Author(s):  
A. Shokohfar ◽  
S. M. Abbasi ◽  
Ali Yazdani ◽  
Behnam Rabiee

In this study, cold rolling and annealing are used to refine the austenite grains of 301 austenitic stainless steel. The 301 austenitic stainless steel was cold rolled for 70 and 90% strain and then annealed. Effects of cold rolling factors and temperatures and annealing times on microstructure, hardness and tensile properties have been studied.

Alloy Digest ◽  
1999 ◽  
Vol 48 (8) ◽  

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.


2007 ◽  
Vol 539-543 ◽  
pp. 4891-4896 ◽  
Author(s):  
P. Antoine ◽  
B. Soenen ◽  
Nuri Akdut

Transformation of austenite to martensite during cold rolling operations is widely used to strengthen metastable austenitic stainless steel grades. Static strain aging (SSA) phenomena at low temperature, typically between 200°C and 400°C, can be used for additional increase in yield strength due to the presence of α’-martensite in the cold rolled metastable austenitic stainless steels. Indeed, SSA in austenitic stainless steel affects mainly in α’-martensite. The SSA response of three industrial stainless steel grades was investigated in order to understand the aspects of the aging phenomena at low temperature in metastable austenitic stainless steels. In this study, the optimization of, both, deformation and time-temperature parameters of the static aging treatment permitted an increase in yield strength up to 300 MPa while maintaining an acceptable total elongation in a commercial 301LN steel grade. Deformed metastable austenitic steels containing the “body-centered” α’-martensite are strengthened by the diffusion of interstitial solute atoms during aging at low temperature. Therefore, the carbon redistribution during aging at low temperature is explained in terms of the microstructural changes in austenite and martensite.


Alloy Digest ◽  
2021 ◽  
Vol 70 (9) ◽  

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.


2017 ◽  
Vol 23 (2) ◽  
pp. 111 ◽  
Author(s):  
Andrea Di Schino ◽  
Maria Richetta

<p>Even if relations predicting the mechanical properties on bars of austenitic stainless steels are already available, but no systematic works was carried out in order to predict mechanical properties in after cold rolling and annealing.   The tensile properties of a large number of cold rolled and annealed AISI 304 stainless steel are here correlated with their chemical composition and microstructure. Quantitative effects of various strengthening mechanisms such as grain size, d– ferrite content and solid solution strengthening by both interstitial and substitutional solutes are described. Interstitial solutes have by far the greatest strengthening effect and, among the substitutional solutes, the ferrite – stabilising elements have a greater effect than the austenite – stabilising elements. Regression equations are developed which predict with good accuracy the proof stress and tensile strength in AISI 304 stainless steels.</p>


Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1845
Author(s):  
Francesca Borgioli ◽  
Emanuele Galvanetto ◽  
Tiberio Bacci

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.


2019 ◽  
Vol 116 (6) ◽  
pp. 618
Author(s):  
Nega Setargew ◽  
Daniel J. Parker

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.


2019 ◽  
Vol 944 ◽  
pp. 193-198
Author(s):  
Tian Yi Wang ◽  
Ren Bo Song ◽  
Heng Jun Cai ◽  
Jian Wen ◽  
Yang Su

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.


2013 ◽  
Vol 718-720 ◽  
pp. 29-32 ◽  
Author(s):  
Xiao Liu ◽  
Yu Bo

The anodic polarization curves of 21Cr-11Ni austenitic stainless steels with various RE contents in 3.5% NaCl neutral solutions have been measured by electrochemical methods. The effect of RE on pitting corrosion resistance of 21Cr-11Ni stainless steels has been studied by the metallographic examination. The results show that sulfide and other irregular inclusions are modified to round or oval-shaped RE2O2S and RES after adding RE to 21Cr-11Ni stainless steesl. RE makes sulfide, and other irregular inclusions change to dispersed round or oval-shaped RE inclusions, effectively inhibits the occurrence of pitting corrosion, thereby enhancing the corrosion resistance of 21Cr-11Ni austenitic stainless steels.


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