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 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.

scholarly journals High Strain Rate Tensile Properties of Annealed 2 1/4 Cr-1 Mo Steel

1976 ◽  
Vol 98 (4) ◽  
pp. 361-368 ◽  
Author(s):  
R. L. Klueh ◽  
R. E. Oakes
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
High Strain Rate ◽  
Strain Rate ◽  
Tensile Properties ◽  
Elevated Temperatures ◽  
High Strain ◽  
Total Elongation ◽  
Major Effect ◽  
Dynamic Strain

The high strain rate tensile properties of annealed 2 1/4 Cr-1 Mo steel were determined and the tensile behavior from 25 to 566°C and strain rates of 2.67 × 10−6 to 144/s were described. Above 0.1/s at 25°C, both the yield stress and the ultimate tensile strength increased rapidly with increasing strain rate. As the temperature was increased, a dynamic strain aging peak appeared in the ultimate tensile strength-temperature curves. The peak height was a maximum at about 350°C and 2.67 × 10−6/s. With increasing strain rate, a peak of decreased height occurred at progressively higher temperatures. The major effect of strain rate on ductility occurred at elevated temperatures, where a decrease in strain rate caused an increase in total elongation and reduction in area.

scholarly journals Microstructure and Mechanical Properties of Structural Steel after Dynamic Cold Working Deformation/ Wpływ Dynamicznego Odkształcenia Plastycznego Na Zimno Na Mikrostrukturę I Własności Stali Konstrukcyjnej

2014 ◽  
Vol 59 (4) ◽  
pp. 1699-1703 ◽  
Author(s):  
J. Pacyna ◽  
R. Dabrowski ◽  
E. Rozniata ◽  
A. Kokosza ◽  
R. Dziurka
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Impact Strength ◽  
Yield Stress ◽  
Cold Working ◽  
Strong Relationship ◽  
The Common ◽  
Reduction Of Area ◽  
Grade Steel

Abstract The results of the selected mechanical properties i.e. ultimate tensile strength (UTS), yield stress (YS), elongation (EL), reduction of area (RA), hardness (HV) and impact strength (KCV) of the common, S235JR grade steel, are presented in the paper. A strong relationship between the above mentioned properties and cooling rates after hot rolling of rods, made of this steel, was found. Additionally, the possibility of further enhancing of mechanical properties (UTS and YS) by the controlled, dynamic cold working, was shown. The use of such deformation, through changes in the microstructure allows for the upper yield stress (YS) increase - app. 10% and ultimate tensile strength UTS - app. 5%. Simultaneously, very high indicators of plasticity (EL, RA) and impact strength (KCV) are retained, as they were immediately after the rolling. The possibility of improving the mechanical properties of rods made of this steel grade has a great technological and commercial importance for its manufacturers, as well as for their final users.

scholarly journals The Influence of Microstructure on the Mechanical Properties and Fracture Behavior of Medium Mn Steels at Different Strain Rates

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4228 ◽  
Author(s):  
Zheng Wang ◽  
Juanping Xu ◽  
Yu Yan ◽  
Jinxu Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Total Elongation ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Car Crash ◽  
Δ Ferrite

The primary task of automotive industry materials is to guarantee passengers’ safety during a car crash. To simulate a car crash, the influence of strain rates on mechanical properties and fracture behavior of medium Mn steels with different Si content (0Si without δ-ferrite and 0.6Si with about 20% δ-ferrite) was conducted using the uniaxial tensile test. The results show that ultimate tensile strength is higher, whereas total elongation is lower in 0Si than in 0.6Si. As the strain rate increases, ultimate tensile strength and total elongation decrease in both 0Si and 0.6Si; nonetheless, total elongation of 0.6Si decreases faster. Meanwhile, the area reduction of 0.6Si increases as the strain rate increases. The microcrack′s number on a rolling direction (RD)-transverse direction (TD) surface is considerably increased; nonetheless, the microcrack′s size is restrained in 0.6Si compared with 0Si. Microcracks start at γ(α′)/α-ferrite interfaces in both 0Si and 0.6Si, whereas little nucleation sites have also been found at (γ(α′)+α-ferrite)/δ-ferrite boundaries in 0.6Si. Meanwhile, δ-ferrite reveals a higher capacity for microcrack arrest. As the strain rate decreases, increased lower crack growth results in fine and even dimples on fractographs with abundant second cracks on fractographs; meanwhile, the small microcrack′s number increases, while the large microcrack′s number decreases on an RD-TD surface.

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.

Effects of Aging on the Mechanical Properties of Pipeline Steels

2008 ◽  
Author(s):  
Martin Hukle ◽  
Brian Newbury ◽  
Dan Lillig ◽  
Jonathan Regina ◽  
Agnes Marie Horn
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Uniform Elongation ◽  
Weld Line ◽  
Base Material ◽  
Pipeline System ◽  
Line Pipe ◽  
Pipeline Steels ◽  
Reduction Of Area ◽  
Effects Of Aging

The intelligent design of a given pipeline system intended for operation beyond the elastic limit should incorporate specific features into both the base material (line pipe) and girth weld that enable the affected system to deform safely into the plastic regime within the intended strain demand limits. The current paper focuses on the mechanical properties known to influence the strain capacity of the base material (i.e., line pipe steel independent of the girth weld). Line pipe mechanical properties of interest include: longitudinal yield strength, tensile strength, yield to tensile strength ratio, reduction of area, elongation and uniform elongation. Of particular interest (in consideration of the conventional thermally applied corrosion protection coating systems to be employed), are the longitudinal mechanical properties in the “aged” condition. The present study investigates six (6) different pipeline steels encompassing grades X60 (415 MPa) to X100 (690 MPa), and includes both UOE Submerged Arc Welded - Longitudinal (SAW-L) and seamless (SMLS) forming methods.

Tensile Properties and Fracture Behavior of SiCp/AC4CH Composite at Loading Velocities of up to 10m/s

2004 ◽  
Vol 449-452 ◽  
pp. 305-308
Author(s):  
Lei Wang ◽  
Toshiro Kobayashi ◽  
Chun Ming Liu
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Tensile Test ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Tensile Deformation ◽  
Optical Microscope ◽  
Fracture Elongation ◽  
Before And After

Tensile test at loading velocities up to 10 m·s-1(strain rate up to 3.2x102s-1) was carried out forr SiCp/AC4CH composite and AC4CH alloy. The microstructure of the composite before and after tensile deformation was carefully examined with both optical microscope and SEM. The experimental results demonstrated that the ultimate tensile strength (UTS) and yield strength (YS) increase with increasing loading velocity up to 10 m·s-1. Comparing with AC4CH alloy, the fracture elongation of the composite is sensitivity with the increasing strain rate. The YS of both the composite and AC4CH alloy shows more sensitive than that of the UTS with the increasing strain rate, especially in the range of strain rate higher than 102s-1.

Fracture Behavior of an AlMgMnSc Alloy at Different Temperatures

2021 ◽  
Vol 1016 ◽  
pp. 292-296
Author(s):  
Yuliya Igorevna Borisova ◽  
Diana Yuzbekova ◽  
Anna Mogucheva
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Brittle Fracture ◽  
Fracture Surface ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Fine Grained ◽  
Angular Pressing ◽  
Different Temperatures ◽  
Elongation To Failure

An Al-4.57Mg-0.35Mn-0.2Sc-0.09Zr (wt. %) alloy was studied in the fine-grained state obtaining after equal channel angular pressing. The mechanical behavior of alloy at the temperatures 173 K, 298 K and 348 K and at strain rate 1×10–3 s–1 is studied. Increase of the temperature testing from 173 K to 348 K decreases the yield stress by 80 MPa, the ultimate tensile strength by 60 MPa while elongation-to failure increases by a factor of 1.4. It was found that at temperatures of 298 and 173 K, the studied alloy mainly demonstrates the mode of ductile fracture, and at a temperature of 348 K the mechanism can be described as mixed ductile-brittle fracture. It was also established that of the studied alloy is the temperature dependence of the size of the dimples on the fracture surface. The formation of smaller dimples in the samples deformed at 298 K was observed.

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