Investigation on Yield Point Elongation and Yield Strength of Fe‐9Mn‐1.5Si‐1Al‐0.05C Steel Water‐Quenched and Air‐Quenched Prior to Intercritical Annealing

2021 ◽  
Author(s):  
Tianle Li ◽  
Shu Yan ◽  
Xianghua Liu
Keyword(s):  
Yield Strength ◽  
Yield Point ◽  
Intercritical Annealing ◽  
Yield Point Elongation

scholarly journals MD INVESTIGATIONS FOR MECHANICAL PROPERTIES OF COPPER NANOWIRES WITH AND WITHOUT SURFACE DEFECTS

2012 ◽  
Vol 09 (01) ◽  
pp. 1240003 ◽  
Author(s):  
Y. T. GU ◽  
H. F. ZHAN
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Yield Strength ◽  
Yield Point ◽  
Surface Defects ◽  
Volume Ratio ◽  
Strain Rates ◽  
Copper Nanowires ◽  
Dislocation Source ◽  
Different Temperatures

Based on the molecular dynamics (MD) method, the single-crystalline copper nanowire with different surface defects is investigated through tension simulation. For comparison, the MD tension simulations of perfect nanowire are first carried out under different temperatures, strain rates, and sizes. It has concluded that the surface–volume ratio significantly affects the mechanical properties of nanowire. The surface defects on nanowires are then systematically studied in considering different defect orientation and distribution. It is found that the Young's modulus is the insensitive of surface defects. However, the yield strength and yield point show a significant decrease due to the different defects. Different defects are observed to serve as a dislocation source.

Review on the Hall-Petch Relation in Ferritic Steel

2010 ◽  
Vol 654-656 ◽  
pp. 11-16 ◽  
Author(s):  
Setsuo Takaki
Keyword(s):  
Grain Size ◽  
Carbon Steel ◽  
Yield Strength ◽  
Yield Point ◽  
Ferritic Steel ◽  
Low Carbon Steel ◽  
Aging Treatment ◽  
Interstitial Free ◽  
Low Carbon ◽  
Petch Relation

Yielding of polycrystalline low carbon steel is characterized by a clear yield point followed by unstable Lüders deformation and such a yielding behavior is taken over to fine grained steel with the grain size of 1μm or less. Yield strength of ferritic steel is increased with grain refinement standing on the Hall-Petch relation. The following equation is realized up to 0.2μm grain size in the relation between yield strength y and grain size d: y [MPa]= 100+600×d[μm]-1/2. In low carbon steel, it might be concluded that the Hall-Petch coefficient (ky) is around 600MPa•μm1/2. However, the ky value of interstitial free steels is substantially small as 130-180MPa•μm1/2 and it can be greatly increased by a small amount of solute carbon less than 20ppm. It was also cleared that the disappearance of yield point by purifying is due to the decrease in the ky value. On the other hand, the ky value is changeable depending on heat treatment conditions such as cooling condition from an elevated temperature and aging treatment at 90°C. These results suggest the contribution of carbon segregation at grain boundary in terms of the change in the ky value. On the contrary, substitutional elements such as Cr and Si do not give large influence to the ky value in comparison with the effect by carbon.

Analysis of Orange Peel Defects on Hot-Dip Galvanized High Strength Low Alloy Steel

2014 ◽  
Vol 1004-1005 ◽  
pp. 221-226
Author(s):  
Li Hui Wang ◽  
Di Tang ◽  
Xiang Dong Liu ◽  
Yan Wen Zhang ◽  
Shi Zheng Zhou
Keyword(s):  
Yield Point ◽  
Hsla Steel ◽  
Sheet Steel ◽  
Rolling Direction ◽  
Orange Peel ◽  
High Strength ◽  
Electron Back Scatter Diffraction ◽  
Steel Rolling ◽  
Yield Point Elongation ◽  
Skin Rolling

The surface of hot-dip galvanized high strength low alloy (HSLA) steel easily occurs orange peel in the deformation process. On the other hand, the defects possess a specific directivity and sits at approximately a 45-degree angle to the sheet steel rolling direction. The microstructures and properties of steel specimens with the orange peel defects and the normal were analyzed, which results showed that their microstructures consist of ferrite and few granular pearlite. The yield point elongation of the HSLA steel resulted in the orange peel defects on the surface of sheet stamping and it is associated with skin rolling and stretch rolling process. Further studied on the fine microstructures by means of SEM and electron back scatter diffraction (EBSD) techniques, which was apparent for the defect steel that the orange peel defects were resulted from weak favorable {111} texture might be the key factors aggravating the formation of orange peel defects. It can be concluded that the formation of Cottrell atmospheres caused the yield point elongation by the interaction between dislocation and diffusive solute atoms as basic reason and the directivity of the orange peel defects was related with the LUDERS slip forming. The yield point elongation can be eliminated to avoid the orange peel defects beyond to 1.8% skin-rolling and stretch rolling method with an appropriate annealing technology.

MHZ 420

Alloy Digest ◽  
2018 ◽  
Vol 67 (12) ◽  
Keyword(s):  
Tensile Strength ◽  
Yield Strength ◽  
Tensile Properties ◽  
Yield Point ◽  
Precipitation Hardening ◽  
High Strength ◽  
Strength Properties ◽  
Cold Forming ◽  
Fine Grained

Abstract MHZ 420 (mininum yield strength of 420 MPa) is one of a series of microalloyed cold forming steels. The high-strength properties result from precipitation hardening thanks to finely-dispersed carbonitrides and a fine-grained microstructure. Even very small amounts of the elements titanium and/or niobium in the region of 0.01% result in a significant increase in the yield point and tensile strength. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-831. Producer or source: ThyssenKrupp Steel Europe AG.

MHZ 380

Alloy Digest ◽  
2018 ◽  
Vol 67 (11) ◽  
Keyword(s):  
Tensile Strength ◽  
Yield Strength ◽  
Tensile Properties ◽  
Yield Point ◽  
Precipitation Hardening ◽  
High Strength ◽  
Strength Properties ◽  
Cold Forming ◽  
Fine Grained

Abstract MHZ 380 (mininum yield strength of 380 MPa) is one of a series of microalloyed cold forming steels. The high-strength properties result from precipitation hardening thanks to finely-dispersed carbonitrides and a fine-grained microstructure. Even very small amounts of the elements titanium and/or niobium in the region of 0.01% result in a significant increase in the yield point and tensile strength. This datasheet provides information on composition and tensile properties as well as fatigue. It also includes information on forming and joining. Filing Code: SA-828. Producer or source: ThyssenKrupp Steel Europe AG.

Strain aging and breakaway strain amplitude of damping in NiAl and NiAlZr

1994 ◽  
Vol 9 (5) ◽  
pp. 1166-1173 ◽  
Author(s):  
A. Wolfenden ◽  
S.V. Raj ◽  
S.K.R. Kondlapudi
Keyword(s):  
Binding Energy ◽  
Yield Strength ◽  
Yield Point ◽  
Strain Amplitude ◽  
Strain Aging ◽  
Room Temperature ◽  
Young Modulus ◽  
Initial Strain Rate ◽  
Order Of Magnitude ◽  
Discontinuous Yielding

Extruded NiAl and NiAlZr alloys often show discontinuous yielding on strain aging in compression at room temperature. Two sets of experiments were conducted to understand the reasons for this yield-point behavior. First, strain-aging experiments were carried out on NiAl alloys containing O to 0.1 at. % Zr. The specimens were all deformed in compression at room temperature at a nominal initial strain rate of 1.1 × 10−4S−1, and the effect of annealing at 700 and 1200 K on the stress-strain curves and the yield strength was studied after an initial prestrain. While annealing at 700 and 1200 K consistently reduced the yield strength of both NiAl and NiAlZr, the effects were quite different. In the case of NiAl, annealing at 1200 K did not result in discontinuous yielding, whereas it generally resulted in a sharp yield point for the Zr containing alloys. Second, the PUCOT (piezoelectric ultrasonic composite oscillator technique) was used to measure the dynamic Young modulus, breakaway strain amplitude, and damping for the alloys. Only small differences were observed in the values of Young's modulus, but the breakaway strain was at least a factor of 2 to 3 lower for NiAl than for NiAlZr. The experimentally determined values of damping were used in the Granato-Lücke model to estimate the binding energy for NiAl. While the binding energy values were found to be in agreement with the calculated values of dislocation kink nucleation and migration energies in this material, to within an order of magnitude, other effects, such as dislocation pinning by quenched-in vacancies, cannot be ruled out. The observations made in this study suggest that the yield-point behavior in NiAl may be due to several factors, such as difficulties in double kink nucleation, and single kink migration, as well as dislocation-vacancy interactions; whereas, the yield-point behavior in the Zr-alloyed material is due at least in part to dislocation-solute interaction.

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