scholarly journals Investigation of Electroplastic Effect on Four Grades of Duplex Stainless Steels

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1911 ◽  
Author(s):  
Claudio Gennari ◽  
Luca Pezzato ◽  
Enrico Simonetto ◽  
Renato Gobbo ◽  
Michele Forzan ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Stress ◽  
Stainless Steels ◽  
Uniform Elongation ◽  
Electrical Current ◽  
Total Elongation ◽  
Duplex Stainless Steels ◽  
Electroplastic Effect ◽  
Two Phases

Since the late 1950s, an effect of electrical current in addition to joule heating on the deformation of metals called the Electroplastic Effect (EPE) has been known. It is used nowadays in the so-called Electrically Assisted Forming (EAF) processes, but the understanding of the phenomenon is not very clear yet. It has been found that EPE increases the formability of high stacking fault energy (SFE) materials, while low SFE materials reach fracture prematurely. Since Duplex Stainless Steels (DSSs) possess a microstructure consisting of two phases with very different SFE (low SFE austenite and high SFE ferrite) and they are widely used in industry, we investigated EPE on those alloys. Tensile tests at 5 A/mm2, 10 A/mm2 and 15 A/mm2 current densities along with thermal counterparts were conducted on UNS S32101, UNS S32205, UNS S32304 and UNS S32750. The DSS grades were characterized by means of optical microscopy, X-ray diffraction and their mechanical properties (ultimate tensile strength, total elongation, uniform elongation and yield stress). An increase in uniform elongation for the electrical tests compared to the thermal counterparts as well as an increase in total elongation was found. No differences were observed on the yield stress and on the ultimate tensile strength. Un uneven distribution of the current because of the different resistivity and work hardening of the two phases has been hypothesized as the explanation for the positive effect of EPE.

Strain Rate Effects on the Elevated-Temperature Tensile Behavior of a Bainitic 2-1/4 Cr-1 Mo Steel

1977 ◽  
Vol 99 (4) ◽  
pp. 350-358 ◽  
Author(s):  
R. L. Klueh ◽  
R. E. Oakes
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Strain Rate ◽  
Yield Stress ◽  
Uniform Elongation ◽  
Constant Strain Rate ◽  
Total Elongation ◽  
Dynamic Strain ◽  
Strain Rate Effects ◽  
Reduction Of Area

The tensile properties of a normalized-and-tempered 2-1/4 Cr-1 Mo steel were determined from 25 to 566° C and the strain rate 2.67 × 10−6 to 144/s. The specimens were taken from a 1-in. thick plate and had a microstructure that was essentially 100 percent bainite. Except at 25 and 566° C, the 0.2 percent yield stress was little affected by strain rate; at 25 and 566° C, the yield stress increased with increasing strain rate. At a constant strain rate, the yield stress decreased with increasing temperature. The effect of strain rate and temperature on the ultimate tensile strength was somewhat more complicated. A strength peak that resulted from dynamic strain aging was observed in the ultimate tensile strength-temperature relationship. The position of these peaks moved to higher temperatures with increasing strain rate. Total elongation and reduction of area were relatively constant over the range of test variables, except at 566° C, where they increased with decreasing strain rate. However, uniform elongation decreased with decreasing strain rate at 510 and 566° C, dropping to 1 and 0.6 percent, respectively.

scholarly journals Influence of mechanical correction on the geometric and mechanical properties of cold-formed periodic profile fittings

2020 ◽  
pp. 48-52
Author(s):  
L. V. Loktionova
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Stress ◽  
Maximum Load ◽  
Total Elongation ◽  
Mechanical Tests ◽  
Test Method ◽  
Ambient Room Temperature ◽  
Manual Testing ◽  
Periodic Profile

The article describes the process of mechanical correction of cold-formed fittings produced in coils on industrial rightsized cutting machines of rotary and roller types. The main qualitative characteristics of the reinforcement are given, such as: ultimate tensile strength, offset yield stress, the ratio of ultimate tensile strength offset yield stress, conditional yield strength, total elongation at maximum load and the relative area of crumpling. To assess the effect of mechanical correction on the properties of cold-formed periodic profile fittings, statistical data is used for testing samples of fittings produced in coils and straightened before manual testing and samples of the same fittings transferred from consumer companies after mechanical correction on right-sized rotary type cut machines.Tensile testing of samples was performed on testing machines in the laboratory of physical and mechanical tests No. 3 of the OJSC «BSW – Management Company of the Holding «BMC» in accordance with the requirements of ISO 15630-1:2010 «Steel for concrete reinforcement and pre-stressing. Test method. Part 1. Reinforcing rods, wire rod and wire» and ISO 6892:2016 «Metal Materials. Tensile test. Part 1. Method of test at ambient room temperature».

scholarly journals Tempering and Austempering of Double Soaked Medium Manganese Steels

2021 ◽  
Vol 7 ◽  
Author(s):  
Alexandra Glover ◽  
John G. Speer ◽  
Emmanuel De Moor
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Retained Austenite ◽  
Bainitic Ferrite ◽  
Total Elongation ◽  
Uniaxial Tensile ◽  
Present Contribution ◽  
Uniaxial Tensile Testing ◽  
Manganese Steels

The addition of a tempering or austempering step to the double soaking of a 0.14C–7.17Mn (wt pct) steel was investigated in the present contribution. The double soaking heat treatment is a two-step intercritical annealing heat treatment, which generates microstructures of athermal martensite, retained austenite and ferrite when applied to medium manganese steels. Microstructures following double soaking and (aus)tempering contained a combination of retained austenite, athermal or tempered martensite, and blocky or bainitic ferrite. X-ray diffraction, dilatometry and transmission Kikuchi diffraction were utilized to investigate microstructural changes which occurred during tempering or austempering. The resulting mechanical properties were measured using uniaxial tensile testing. The double soaking plus tempering heat treatment was shown to generate an ultimate tensile strength of 1,340 MPa in combination with 28 pct total elongation while the double soaking plus austempering heat treatment resulted in an ultimate tensile strength of 1,675 MPa and total elongation of 22 pct. Overall, both novel heat treatments produced a combination of strength and ductility desired for the third generation of advanced high strength steels.

Thickness-Dependent Tensile Behavior of Cu-Mn Alloys under Different Dislocation Slip Modes

2019 ◽  
Vol 294 ◽  
pp. 104-110 ◽  
Author(s):  
Le Le Kang ◽  
Dong Han ◽  
Xiao Wu Li
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Size Effect ◽  
Uniform Elongation ◽  
Tensile Behavior ◽  
Dislocation Slip ◽  
Slip Mode ◽  
Planar Slip ◽  
Metallic Materials

To explore the role of dislocation slip mode playing in the size effect of mechanical behavior of metallic materials, the tensile behavior of Cu-5at.%Mn and Cu-20at.%Mn alloys with thickness (t) spanning from 0.1 to 2.0 mm is investigated. The results reveal that the yield strength σYS of Cu-5at.%Mn alloy displays an independence of thickness, whereas the ultimate tensile strength σUTS and the uniform elongation δ show an obvious size effect. The σUTS and δ first slightly decrease as t is reduced from 2.0 to 0.5 mm, but evidently drop when t is below 0.5 mm. A similar size effect is also exhibited in Cu-20at.%Mn alloy; however, the variation trend of “the smaller the weaker” in size effect can be weakened by the planar slip of dislocations occurring during the deformation of this alloy.

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.

Development of Laminar Flow Cooling of Ultra-High Strength Ferrite-Bainite Dual Phase Steel

2012 ◽  
Vol 184-185 ◽  
pp. 940-943
Author(s):  
Wei Lv ◽  
Di Wu ◽  
Zhuang Li
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Laminar Flow ◽  
Hot Rolling ◽  
Retained Austenite ◽  
High Strength ◽  
Total Elongation ◽  
Granular Bainite ◽  
Dual Phase ◽  
Dp Steel

In the present paper, controlled cooling in different ways was performed using a laboratory hot rolling mill in ultra-high strength hot rolled ferrite-bainite dual phase (DP) steel. The results have shown that the final microstructures of DP steel comprise ferrite, bainite and a small amount of retained austenite and martensite. DP steel has a tensile strength ranging from 1010 to 1130MPa and yet retains considerable total elongation in the range of 14–17%. The addition of Mn and Nb to DP steel leads to the maximum ultimate tensile strength, yield strength and the product of ultimate tensile strength and total elongation due to the formation of retained austenite and granular bainite structure. Laminar flow cooling after hot rolling results in a significant increase in the quantity of ferrite and bainite due to the suppression of pearlite transformation, and as a result, the present steel possesses high strengths and good toughness.

Influence of Grain Size on Mechanical Properties of AZX311 Alloy

2013 ◽  
Vol 753 ◽  
pp. 473-476 ◽  
Author(s):  
Naoto Sakai ◽  
Kunio Funami ◽  
Masafumi Noda ◽  
Hisashi Mori ◽  
Kenji Fujino
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Total Elongation ◽  
Growth Behavior ◽  
Rolled Material ◽  
Annealing Temperatures ◽  
Grain Growth Behavior

In the present study, the grain refinement, grain growth behavior, and tensile properties of rolled and annealed AZX311 Mg alloys were investigated. The yield strength and ultimate tensile strength of the rolled material were 360 MPa and 370 MPa, respectively, and the total elongation was 5%. When annealing was performed at 423 K for 1hr, the yield strength and ultimate tensile strength were unchanged, but the elongation increased to 10%. Furthermore, the strength and elongation did not change for annealing temperatures of 473–673 K owing to Al2Ca precipitations.

scholarly journals Kearns texture parameters, mechanical properties and damageability of titanium sheet after alternating bending

2021 ◽  
Vol 22 (3) ◽  
pp. 543-550
Author(s):  
V.V. Usov ◽  
N.M. Shkatulyak ◽  
O.S. Savchuk ◽  
N.I. Rybak
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
Yield Stress ◽  
Rolling Direction ◽  
Initial State ◽  
Texture Parameters ◽  
Experimental Values ◽  
Alternating Bending

This work aims to determine the Kearns texture parameters and evaluate on their basis the elastic moduli, mechanical properties (ultimate tensile strength, conditional yield stress), as well as damageability parameters of the sheets commercial titanium (CT-grade 1: 0.04% Fe; 0.015% C; 0.05% N 0.05% c; 0.009% H)  as delivered after rolling and annealing at 840°C (original sheet) and further alternating bending (AB) in the amount of 0.5; 1, 3 and 5 cycles. Damageability parameters characterizing damage accumulation were determined from the elastic modulus change after the above-mentioned number of AB cycles relative to the values ​​of the elastic modulus in different directions of the original sheet of the studied titanium. The elastic constants of the single crystal and the Kearns texture parameters were used to estimate the elastic modulus in the rolling direction (RD) and transverse direction (TD) of the original sheet, and sheets after an above number of AB cycles. The deviation of the calculated and experimental values ​​of the elastic modulus did not exceed 5%. The deviation of the calculated and experimental values of the ultimate tensile strength and yield stress in the RD and TD both in the initial state and after the corresponding number cycles of the AB did not exceed 10%.

Reinforcing Inconel 718 Superalloy by Nano-TiC Particles in Selective Laser Melting

2015 ◽  
Author(s):  
Yachao Wang ◽  
Jing Shi ◽  
Yun Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Additive Manufacturing ◽  
Ultimate Tensile Strength ◽  
Yield Stress ◽  
Selective Laser Melting ◽  
Inconel 718 ◽  
Reinforcement Particle ◽  
Manufacturing Processes ◽  
Laser Melting

Metal components produced by additive manufacturing processes usually have inferior properties and performances as compared with the counterparts by the traditional forming and machining processes. To close the gap, the metal matrix can be strengthened by adding reinforcement particles in additive manufacturing processes. This research presents the fabrication of nano-TiC reinforced Inconel 718 composites using selective laser melting (SLM). Tensile and wear performance tests are conducted to evaluate the mechanical properties of the formed composites. It is discovered that the composites exhibit improved mechanical properties in terms of ultimate tensile strength and yield stress. Compared with the pure Inconel 718 specimens by SLM, the ultimate tensile strength and yield stress of the reinforced Inconel 718 increase by 207 MPa and 204 MPa, respectively, with 0.5 wt.% addition of nano-TiC particle. Smaller increases are observed with 0.25 wt.% and 1.0 wt.% nano-TiC additions. On the other hand, the addition of nano-TiC particles decreases the ductility of Inconel 718. To investigate the strengthening mechanism of nano reinforcement particles in SLM, the microstructures with different levels of nano-TiC particles are observed. The results indicate that the microstructure of Inconel 718 is remarkably refined by the TiC particles, and the reinforcement particle significantly impede the growth of columnar grain in the solidification process.

Microstructure and Tensile Properties of a 1.25Cr-0.5Mo Main Steam Pipe After Long-Term Service

2018 ◽  
Author(s):  
Bin Yang ◽  
Wen-Chun Jiang ◽  
Wen-Qi Sun ◽  
Yan-Ling Zhao ◽  
Wei-Ya Zhang
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Tensile Properties ◽  
Yield Stress ◽  
Tensile Deformation ◽  
High Yield ◽  
Micro Hardness ◽  
Steam Pipe ◽  
Main Steam

Metallographic tests, micro-hardness tests and tensile tests were conducted for a 1.25Cr-0.5Mo main steam pipe weldment served for more than 26 years. The results were compared with those for virgin material. Microstructural evolution of 1.25Cr-0.5Mo base metal was investigated. Degradation in micro-hardness and tensile properties were also studied. In addition, the tensile properties of subzones in the ex-service weldment were characterized by using miniature specimens. The results show that obvious microstructural changes including carbide coarsening, increasing inter lamella spacing and grain boundary precipitates take place after long-term service. Degradation in micro-hardness is not obvious. However, the effects of long term service on tensile deformation behavior, ultimate tensile strength and yield stress are remarkable. Based on the yield stress of micro-specimens, the order of different subzones is: WM > HAZ > BM, which is consistent with the order of different subzones based on micro-hardness. However, the ultimate tensile strength and fracture strain of HAZ are lower than BM. Brittle failures can happen more easily for HAZ due to its high yield ratio.

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