Random Critical Fracture Toughness Values of China Railway Grade B Cast Steel Wheel

2011 ◽  
Vol 480-481 ◽  
pp. 381-386
Author(s):  
Lei Chen ◽  
Yong Xiang Zhao ◽  
Guo Xiang Song
Keyword(s):  
Fracture Toughness ◽  
Structural Damage ◽  
Cast Steel ◽  
Comparison Method ◽  
Growth Direction ◽  
Steel Wheel ◽  
Quantitative Measurements ◽  
Critical Fracture ◽  
Plastic Dissipation ◽  
Damage Process

Fracture surface observations and statistical deriving are applied for investigating the random critical fracture toughness values of China grade B cast steel wheel. Results reveal that: the crack grows to show fabric like stripes along the growth direction with few of dimples. Cleavage flowers appear under higher magnification. Cracked structural damage process is verified with few of plastic dissipation. At the same time, code based evaluated results indicate that significant scatter exists for the toughness values. Lognormal modeling is constructed appropriately with a comprehensive statistical comparison method. It is verified that random characters and quantitative measurements have been well depicted for the present critical fracture toughness values.

Random Mechanical Properties of China Railway Grade B Cast Steel Wheel

2011 ◽  
Vol 480-481 ◽  
pp. 179-183
Author(s):  
J.Y. Liu ◽  
Yong Xiang Zhao ◽  
Guo Xiang Song
Keyword(s):  
Mechanical Properties ◽  
Cast Steel ◽  
Comparison Method ◽  
Dissipation Process ◽  
Statistical Comparison ◽  
Steel Wheel ◽  
Quantitative Measurements ◽  
Lotus Flower ◽  
Plastic Dissipation ◽  
Monotonic Load

Random mechanical properties are experimentally studied on China grade B cast steel wheel. Significant dimples and fabric-like tearing signs were observed firstly and then, lotus flower-like cleavage fracture faces were appeared to indicate the material subjected to a plastic dissipation process under monotonic load. Randomness appears in the deformation process companied with a similarity in total and significant differences in local. Appropriate statistical description is explored with a comprehensive statistical comparison method. Lognormal distribution is excavated out by comparison from seven possible statistical models. Random characters and quantitative measurements have been given for the mechanical properties of China grade B cast steel wheel.

Random Fatigue Crack Growth Rates of China Railway Grade B Cast Steel Wheel

2011 ◽  
Vol 480-481 ◽  
pp. 387-392
Author(s):  
Yong Xiang Zhao ◽  
Bing Yang ◽  
Guo Xiang Song
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Rates ◽  
Cast Steel ◽  
Growth Direction ◽  
Steel Wheel ◽  
Plastic Dissipation ◽  
Crack Growth Rates ◽  
Random Fatigue

Fracture surface observations and statistical deriving are applied for the present investigation on the random fatigue crack growth rates of China grade B cast steel wheel. Results reveal that: the crack grows with relative regular initial tip companied fabric like stripes along the growth direction but few of fatigue striations, and then, cleavage flowers appearing on the district of transient fracture with few of dimples. It indicates that sharp notched structural crack behaviour acts as a few of plastic dissipation process. Non-linear statistical modeling covering entire three pieces of fatigue crack growth is constructed for describing the random crack growth rates. Scattered randomness of the growth rates has been well characterized.

Random Fatigue Cracking Thresholds of China Railway Grade B Cast Steel Wheel

2011 ◽  
Vol 480-481 ◽  
pp. 375-380
Author(s):  
Bing Yang ◽  
Yong Xiang Zhao ◽  
Guo Xiang Song
Keyword(s):  
Growth Rate ◽  
Cast Steel ◽  
Fatigue Cracking ◽  
Growth Direction ◽  
Test Results ◽  
Dissipation Process ◽  
Steel Wheel ◽  
Fatigue Striations ◽  
Plastic Dissipation ◽  
Random Fatigue

Fracture surface observations and statistical deriving are applied experimentally for the present investigation on random fatigue cracking thresholds of China grade B cast steel wheel. Results reveal that: the crack grows with relative regular initial tip companied fabric like stripes along the growth direction but few of fatigue striations and then, cleavage flowers appearing on the district of transient fracture with few of dimples. This indicates that sharp notched structures may be subjected to a little plastic dissipation process. In the same time, non-linear statistical modeling is constructed for describing the random crack growth and then, random fatigue cracking thresholds are measured at specified growth rate. The measurements hold a same growth rate which can not be obtained directly from test results.

Scale and Surface Machining Quality Effect on Fatigue Properties for China Railway Grade B Cast Steel Wheel

2011 ◽  
Vol 480-481 ◽  
pp. 363-368
Author(s):  
Yong Xiang Zhao ◽  
Bing Yang ◽  
Y. Li
Keyword(s):  
Fatigue Cracks ◽  
Cast Steel ◽  
Fatigue Behaviour ◽  
Fatigue Properties ◽  
Surface Machining ◽  
Linear Effect ◽  
Steel Wheel ◽  
Damage Process ◽  
China Railway ◽  
Random Fatigue

Synthetic method is studied on assessing scale and surface machined effect on fatigue lives of China railway grade B cast steel wheel. Three kinds of specimens are applied for revealing the non-linear effect with scale kinetics at a least of cost. And 8 to 9 samples are applied for each kind of specimen to reveal the random fatigue behaviour. Assessing work is carried out on a phase of fatigue lives with scale kinetics at a specified strength. Results reveal that fatigue cracks were initiated from the specimen surface having a bigger site and the fatigue damage process companied with less plastic deformation than the material specimens. Random effects on fatigue lives and effect factors are constructed for measuring effects. Statistical character of the test data has been well described.

Fatigue Reliability Curves for China Railway Grade B Cast Steel Wheel

2011 ◽  
Vol 480-481 ◽  
pp. 352-356
Author(s):  
H.Q. Liang ◽  
Yong Xiang Zhao ◽  
Y. Li
Keyword(s):  
Test Data ◽  
Fatigue Cracks ◽  
Cast Steel ◽  
Growth Direction ◽  
Extrapolation Method ◽  
Fatigue Reliability ◽  
Cyclic Plastic ◽  
Steel Wheel ◽  
Fatigue Striations ◽  
Long Life

Four grouped rectangle specimens with thirty four samples, plus eighteen samples for fatigue limits, are tested for constructing the fatigue reliability curves of China grade B cast steel wheel. It reveals that fatigue cracks commonly initiated from the surface weakest phases and grew with typical fatigue striations and sub-cracks perpendicular to the growth direction. Cyclic plastic seems to be strengthened as cyclic stressing level increasing. Fatigue reliability curves are constructed on a consideration of addressing the real super long life. They are evaluated by a concurrent probability extrapolation method. And the measured curves verified that appropriate description has been reached on the test data.

Cyclic Deformation Behaviour of China Railway Grade B Cast Steel Wheel

2011 ◽  
Vol 480-481 ◽  
pp. 306-310 ◽  
Author(s):  
Yong Xiang Zhao ◽  
Guo Xiang Song
Keyword(s):  
Cyclic Deformation ◽  
Deformation Behaviour ◽  
Cast Steel ◽  
Cyclic Stress ◽  
Step Method ◽  
Steel Wheel ◽  
Loading Mode ◽  
Plastic Dissipation ◽  
Incremental Step ◽  
Yielding Point

Cyclic deformation behaviour is experimentally investigated using an incremental step method under a spectrum straining block loading mode for China grade B cast steel wheel. Results reveal that the material acts cyclically as non-Masing behaviour with a Bausinger effect. Different from monotonic tensile situation, material under fatigue loads was subjected to a plastic dissipation process without a yielding sign. Fatigued areas of specimen fracture surfaces are around 35%. Cyclic stress-strain (CSS) curve exhibits constant lower than monotonic tensile curve. Difference is enlarged as strain level increasing in elastic regime of the monotonic deformation. And this difference sustains a level of around 100 MPa as over yielding point. In addition, randomness is also observed for the present cyclic deformations. It indicates that random CSS relations should be comprehensively applied even if under stress based fatigue analysis.

BOFORS 2RM2

Alloy Digest ◽  
1965 ◽  
Vol 14 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Low Temperature ◽  
Mechanical Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Cast Steel ◽  
Heat Treating ◽  
High Mechanical Strength ◽  
Temperature Performance

Abstract BOFORS 2RM2 is a hardenable stainless cast steel having good weldability, high mechanical strength and improved corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low temperature performance and corrosion resistance as well as casting, forming, heat treating, machining, and joining. Filing Code: SS-169. Producer or source: Aktiebolaget Bofors.

Mechanical properties of NiAl-Mo composites produced by specially controlled directional solidification

2012 ◽  
Vol 1516 ◽  
pp. 255-260 ◽  
Author(s):  
G. Zhang ◽  
L. Hu ◽  
W. Hu ◽  
G. Gottstein ◽  
S. Bogner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Directional Solidification ◽  
Creep Resistance ◽  
Room Temperature ◽  
Growth Direction ◽  
Nominal Composition ◽  
Potential Candidate ◽  
In Situ Composites

ABSTRACTMo fiber reinforced NiAl in-situ composites with a nominal composition Ni-43.8Al-9.5Mo (at.%) were produced by specially controlled directional solidification (DS) using a laboratory-scale Bridgman furnace equipped with a liquid metal cooling (LMC) device. In these composites, single crystalline Mo fibers were precipitated out through eutectic reaction and aligned parallel to the growth direction of the ingot. Mechanical properties, i.e. the creep resistance at high temperatures (HT, between 900 °C and 1200 °C) and the fracture toughness at room temperature (RT) of in-situ NiAl-Mo composites, were characterized by tensile creep (along the growth direction) and flexure (four-point bending, vertical to the growth direction) tests, respectively. In the current study, a steady creep rate of 10-6s-1 at 1100 °C under an initial applied tensile stress of 150MPa was measured. The flexure tests sustained a fracture toughness of 14.5 MPa·m1/2at room temperature. Compared to binary NiAl and other NiAl alloys, these properties showed a remarkably improvement in creep resistance at HT and fracture toughness at RT that makes this composite a potential candidate material for structural application at the temperatures above 1000 °C. The mechanisms responsible for the improvement of the mechanical properties in NiAl-Mo in-situ composites were discussed based on the investigation results.

The Influence of Mobile Dislocation Density on the Fracture Toughness of B2-Based Ni-Fe-Al Alloys

1994 ◽  
Vol 350 ◽  
Author(s):  
A. Misra ◽  
R. D. Noebe ◽  
R. Gibala
Keyword(s):  
Fracture Toughness ◽  
Dislocation Density ◽  
Tensile Ductility ◽  
Growth Direction ◽  
Mobile Dislocation ◽  
Second Phase ◽  
Mobile Dislocation Density ◽  
Dislocation Generation ◽  
Multiphase Materials ◽  
Β Phase

AbstractThe deformation and fracture behaviors of two directionally solidified multi-phase Ni-Fe-Al ordered alloys were investigated. One alloy consisted of continuous β+γ lamellae with fine γ precipitates within the γ phase. The NiAl-based β phase of this alloy exhibited <100> slip even when deformed parallel to the [001] growth direction. This material exhibited an initiation fracture toughness of ∼ 30 MPa √m and tensile ductility of 10%. The second alloy consisted of aligned but discontinuous γ lamellae within a continuous β phase. Again, the γ phase contained γ precipitates, but unlike the previous alloy, the β phase also contained a fine dispersion of bcc precipitates due to spinodal decomposition. The β phase of this alloy deformed by <111> slip. This four-phase alloy exhibited a fracture toughness of ∼ 21 MPa √m and tensile ductility of 2%. Observations of the plastic zone in both alloys indicated significant plasticity in the β phase due to easy slip transfer from the ductile second phase. The enhanced fracture resistance of these multiphase materials compared to single phase β alloys is attributed in large part to intrinsic toughening of the β phase by an increased mobile dislocation density due to efficient dislocation generation from the β/γ interfaces.

Fracture Toughness of Ductile Iron and Cast Steel

2008 ◽  
pp. 75-75-20 ◽  
Author(s):  
WL Bradley ◽  
KE McKinney ◽  
PC Gerhardt
Keyword(s):  
Fracture Toughness ◽  
Ductile Iron ◽  
Cast Steel
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