scholarly journals Temperature Dependence of Fracture Characteristics of Variously Heat-Treated Grades of Ultra-High-Strength Steel: Experimental and Modelling

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5875
Author(s):  
Jaroslav Pokluda ◽  
Ivo Dlouhý ◽  
Marta Kianicová ◽  
Jan Čupera ◽  
Jana Horníková ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Temperature Dependence ◽  
High Stress ◽  
Stress Triaxiality ◽  
High Strength ◽  
Fracture Mechanisms ◽  
Temperature Range ◽  
Heat Treated ◽  
Shape Ratio ◽  
Standard Steel

The temperature dependence of tensile characteristics and fracture toughness of the standardly heat-treated low-alloyed steel OCHN3MFA along with three additionally heat-treated grades was experimentally studied. In the temperature range of ⟨−196; 22⟩ °C, all the additional heat treatments transferred the standard steel from a high- to ultra-high strength levels even with improved tensile ductility characteristics. This could be explained by a reduction of the inclusion content, refinement of the martensitic blocks, ductile retained austenite content, and homogenization of the shape ratio of martensitic laths as revealed by metallographic, X-ray, and EBSD techniques. On the other hand, the values of the fracture toughness of all grades were found to be comparable in the whole temperature range as the cause of a high stress triaxiality in the pre-cracked Charpy V-notch samples. The values of the fracture toughness of the standard steel grade could be predicted well using the fracture model proposed by Pokluda et al. based on the tensile characteristics. Such a prediction failed in the case of additionally heat-treated grades due to the different temperature dependence of the fracture mechanisms occurring in the tensile and fracture-toughness tests. While the tensile samples fractured in a ductile-dimple mode at all temperatures, the fracture-toughness specimens exhibited a transition from the ductile to quasi-brittle fracture mode with decreasing temperature. This transition could be interpreted in terms of a transfer from the model proposed by Rice and Johnson to the model of Tvergaard and Hutchinson.

UNS A03560

Alloy Digest ◽  
1986 ◽  
Vol 35 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Strength ◽  
Heat Treating ◽  
Casting Alloy ◽  
Aluminum Casting ◽  
Good Resistance ◽  
Aluminum Casting Alloy ◽  
Temperature Performance ◽  
Heat Treated

Abstract UNS No. A03560 is a heat-treatable aluminum casting alloy. Normally it is used only when heat-treated (aged) strengths are required. It is recommended for high-strength, pressure-tight castings, intricate shapes and where good resistance to corrosion is needed. Its many applications include crank cases, gear cases, oil pans, airframe fittings and instrument housings. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-274. Producer or source: Various aluminum companies.

FEDERATED F401.5Ni

Alloy Digest ◽  
1974 ◽  
Vol 23 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Elevated Temperatures ◽  
High Strength ◽  
Heat Treating ◽  
Casting Alloy ◽  
Aluminum Casting ◽  
Aluminum Casting Alloy ◽  
Treated Condition ◽  
Heat Treated ◽  
Heat Treated Condition

Abstract FEDERATED F401.5Ni is a heat-treatable aluminum casting alloy with high strength and good wear resistance in the fully heat-treated condition. It is recommended for castings requiring good strength at elevated temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-212. Producer or source: Federated Metals Corporation, ASARCO Inc..

INLAND DURASPRING

Alloy Digest ◽  
1998 ◽  
Vol 47 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Tensile Properties ◽  
High Stress ◽  
High Strength ◽  
Spring Steel ◽  
Fatigue Properties ◽  
Light Truck ◽  
Suspension Systems ◽  
Spring Steels

Abstract Inland DuraSpring is a high-strength microalloyed spring steel for use in high stress coil springs for automobile and light truck suspension systems. This bar product offers significant improvements in tensile strength, fatigue properties, and fracture toughness compared to conventional spring steels. This datasheet provides information on composition, hardness, and tensile properties as well asfracture toughness and fatigue. Filing Code: SA-496. Producer or source: Ispat Inland Inc.

BETHSTAR 60

Alloy Digest ◽  
1986 ◽  
Vol 35 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Steel Plate ◽  
High Stress ◽  
High Strength ◽  
Heat Treating ◽  
Low Carbon ◽  
Bethlehem Steel Corporation ◽  
Low Sulfur ◽  
Minimum Yield

Abstract BethStar 60 steel plate is a high-strength product with a 60,000 psi minimum yield strength. It contains low carbon and low sulfur and has outstanding toughness, weldability and formability. It provides the design engineer with a an economical high-strength low-alloy (HSLA) grade that can be fabricated readily. Applications include weight-sensitive components subject to high stress such as frames for large off-highway haulers. This datasheet provides information on composition, physical properties, microstructure, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, and joining. Filing Code: SA-421. Producer or source: Bethlehem Steel Corporation.

Variations in Fracture Toughness for Alloy 718 Given a Modified Heat Treatment

1990 ◽  
Vol 112 (1) ◽  
pp. 116-123 ◽  
Author(s):  
W. J. Mills ◽  
L. D. Blackburn
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Fracture Mechanisms ◽  
Alloy 718 ◽  
Percent Confidence Level ◽  
Heat Treated ◽  
Curve Method ◽  
Heat Treated Condition ◽  
The Impact ◽  
Product Forms

Heat-to-heat and product-form variations in the JIC fracture toughness for Alloy 718 were characterized at 24, 427, and 538°C using the multiple-specimen JR-curve method. Six different material heats along with three product forms from one of the heats were tested in the modified heat treated condition. This heat treatment was developed at Idaho National Engineering Laboratory to improve the impact toughness for Alloy 718 weldments, but it has also been found to enhance the fracture resistance for the base metal. Statistical analysis of test results revealed four distinguishable JIC levels with mean toughness levels ranging from 87 to 190 kJ/m2 at 24°C. At 538°C, JIC values were 15 to 20 percent lower than room temperature toughness levels. Minimum expected values of JIC (ranging from 72 kJ/m2 at 24°C to 48 kJ/m2 at 538°C) and dJR/da (27 MPa at 24 to 538°C) were established based on tolerance intervals bracketing 90 percent of the lowest JIC and dJR/da populations at a 95 percent confidence level. Metallographic and fractographic examinations were performed to relate key microstructural features and operative fracture mechanisms to macroscopic properties.

scholarly journals Cracking and Toughening Mechanisms in Nanoscale Metallic Multilayer Films: A Brief Review

2018 ◽  
Vol 8 (10) ◽  
pp. 1821 ◽  
Author(s):  
Qing Zhou ◽  
Yue Ren ◽  
Yin Du ◽  
Dongpeng Hua ◽  
Weichao Han
Keyword(s):  
Fracture Toughness ◽  
High Strength ◽  
Plastic Instability ◽  
Multilayer Films ◽  
Fracture Mechanisms ◽  
Toughening Mechanisms ◽  
Individual Layer ◽  
Practical Applications ◽  
Mechanical Responses ◽  
The Individual

Nanoscale metallic multilayer films (NMMFs) have captured scientific interests on their mechanical responses. Compared with the properties of monolithic films, multilayers possess unique high strength as the individual layer thickness reduces to the nanoscale, which is benefited from the plentiful hetero-interfaces. However, NMMFs always exhibit a low fracture toughness and ductility, which seriously hinders their practical applications. While there have been reviews on the strengthening and deformation mechanisms of microlaminate, rapid developments in nanotechnology have brought an urgent requirement for an overview focused on the cracking and toughening mechanisms in nanoscale metallic multilayers. This article provides an extensive review on the structure, standard methodology and fracture mechanisms of NMMFs. A number of issues about the crack-related properties of NMMFs have been displayed, such as fracture toughness, wear resistance, adhesion energy, and plastic instability. Taken together, it is hoped that this review will achieve the following two purposes: (1) introducing the size-dependent cracking and toughness performance in NMMFs; and (2) offer a better understanding of the role interfaces displayed in toughening mechanisms. Finally, we list a few questions we concerned, which may shed light on further development.

X-ray Fractographic Study on Alumina and Zirconia Ceramics

1990 ◽  
Vol 34 ◽  
pp. 719-727 ◽  
Author(s):  
Sumio Tanaka ◽  
Yukio Hirose ◽  
Keisuke Tanaka
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
Fracture Surface ◽  
High Strength Steels ◽  
High Strength ◽  
Fatigue Tests ◽  
Fracture Mechanisms ◽  
Zirconia Ceramics ◽  
X Ray ◽  
Fractographic Study

The residual stress left on the fracture surface is one of the important parameters in X-ray fractographic study. It has been used to analyze fracture mechanisms in fracture toughness and fatigue tests especially of high strength steels.In this paper, X-ray fractography was applied to brittle fracture of alumina (Al2O3) and zirconia (ZΓO2) ceramics.

Constraint Based Fracture Assessment of Seam-Welded Pipes Containing Axial Flaws

2006 ◽  
Author(s):  
Yuri Tkach ◽  
Anthony Horn ◽  
Adam Bannister ◽  
Edmund Bolton
Keyword(s):  
Fracture Toughness ◽  
Crack Depth ◽  
High Stress ◽  
Stress Triaxiality ◽  
Single Edge ◽  
Fracture Toughness Testing ◽  
Single Edge Notch ◽  
Seam Weld ◽  
Edge Notch ◽  
Toughness Testing

An Engineering Critical Assessment (ECA) of a pipeline containing an axial defect is usually conservative if standard fracture test pieces are used for the fracture toughness testing. Conventional fracture toughness testing standards employ specimens containing deep cracks in order to guarantee conditions leading to high stress triaxiality and crack-tip constraint. In the current work, single edge notch bend (SENB) and single edge notch tension (SENT) test specimens of two different a/W (crack depth/specimen width) ratios (0.15 and 0.6) were used to obtain HAZ fracture toughness of a seam weld. The influence of specimen geometry and a/W ratio on fracture toughness was investigated. The Master Curve methodology was employed to characterise HAZ fracture toughness of the seam weld in the ductile-to-brittle transition region. The reference temperature T0 was estimated using the test results obtained on specimens of different geometries and constraint levels. A series of ECAs of the pipe containing a surface axial flaw was performed and the benefits of a constraint based fracture mechanics analysis were demonstrated.

Prediction of Fracture Toughness Temperature Dependence Over a Wide Temperature Range Using Simplified and Direct Scaling Method

2018 ◽  
Author(s):  
Takashi Inoue ◽  
Toshiyuki Meshii
Keyword(s):  
Fracture Toughness ◽  
Temperature Dependence ◽  
Yield Stress ◽  
Wide Temperature Range ◽  
Fracture Load ◽  
Specimen Thickness ◽  
Temperature Range ◽  
Direct Scaling ◽  
Wide Range ◽  
Mc Method

The fracture toughness KJc of the material in the ductile to brittle transition temperature (DBTT) range exhibits both test specimen thickness (TST) dependence and temperature dependence. Attention has been paid to the master curve (MC) method, which provides an engineering approach to address these two issues. Although MC is intended to be applied to arbitrary ferritic material whose yield stress is within the range of 275 to 825 MPa, the KJc value must be obtained to determine the material dependent reference temperature T0. The applicable range of MC method is restricted to T0 ± 50 °C. Previous studies indicate that additional pre-tests to obtain T0 are necessary; thus, there might be some unwritten requirement to the test temperature for the KJc temperature dependence prediction in MC method to work effectively. If testing must be conducted for the material of interest at some restricted temperature, a more flexible KJc temperature dependence prediction can possibly be obtained for a wide temperature range in the DBTT range, if the simplified and direct scaling (SDS) method, which predicts fracture “load” from yield stress temperature dependence proposed previously is applied. In this study, the SDS method was applied to two different steels: Cr-Mo steel JIS SCM440 and 0.55% carbon steel JIS S55C. Both tensile and fracture toughness tests were performed over a wide range of temperatures, specifically, −166 to 100 °C for SCM440 and −166 to 20 °C for S55C. The SDS method (i.e., fracture load is proportional to 1/(yield stress)) was initially validated for the specimens in the DBTT range. Finally, a simplified method was proposed and initially validated to predict the KJc temperature dependence, by applying the SDS using the EPRI plastic J functional form.

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