Some Fracture Mechanics Correlations

1968 ◽  
Vol 10 (4) ◽  
pp. 329-336
Author(s):  
L. P. Pook
Keyword(s):  
Mechanical Properties ◽  
Fracture Mechanics ◽  
Tensile Test ◽  
High Strength Steels ◽  
High Strength ◽  
Gauge Length ◽  
Published Data ◽  
Square Root ◽  
Beryllium Copper ◽  
Reduction Of Area

The results of tests on two high-strength steels, beryllium copper and perspex, together with some published data on high-strength steels were examined to see whether there was any relationship between the fracture mechanics parameter K1C and conventional mechanical properties. It was found that for steels and beryllium copper a correlation appeared to exist between K1C and the zero gauge length strain (= Z/(1 - Z) where Z is the reduction of area measured in a tensile test). It was also found that for constant, K1C was proportional to the square root of Young's modulus. The correlation band for steels was too wide for K1C to be estimated accurately from.

scholarly journals Comprehensive Analysis of the Microstructure and Mechanical Properties of Friction-Stir-Welded Low-Carbon High-Strength Steels with Tensile Strengths Ranging from 590 MPa to 1.5 GPa

2021 ◽  
Vol 11 (12) ◽  
pp. 5728
Author(s):  
HyeonJeong You ◽  
Minjung Kang ◽  
Sung Yi ◽  
Soongkeun Hyun ◽  
Cheolhee Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Joint Strength ◽  
Solid Phase ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
Friction Stir ◽  
Welding Processes

High-strength steels are being increasingly employed in the automotive industry, requiring efficient welding processes. This study analyzed the materials and mechanical properties of high-strength automotive steels with strengths ranging from 590 MPa to 1500 MPa, subjected to friction stir welding (FSW), which is a solid-phase welding process. The high-strength steels were hardened by a high fraction of martensite, and the welds were composed of a recrystallized zone (RZ), a partially recrystallized zone (PRZ), a tempered zone (TZ), and an unaffected base metal (BM). The RZ exhibited a higher hardness than the BM and was fully martensitic when the BM strength was 980 MPa or higher. When the BM strength was 780 MPa or higher, the PRZ and TZ softened owing to tempered martensitic formation and were the fracture locations in the tensile test, whereas BM fracture occurred in the tensile test of the 590 MPa steel weld. The joint strength, determined by the hardness and width of the softened zone, increased and then saturated with an increase in the BM strength. From the results, we can conclude that the thermal history and size of the PRZ and TZ should be controlled to enhance the joint strength of automotive steels.

Investigations on the Mechanical Properties and Formability of Friction Stir Welded Tailored Blanks

2007 ◽  
Vol 344 ◽  
pp. 143-150 ◽  
Author(s):  
Gianluca Buffa ◽  
Livan Fratini ◽  
Marion Merklein ◽  
Detlev Staud
Keyword(s):  
Mechanical Properties ◽  
Stress Condition ◽  
Research Effort ◽  
High Strength Steels ◽  
High Strength ◽  
Tensile Tests ◽  
Friction Stir ◽  
Tailored Blanks ◽  
Sheet Stamping ◽  
Wide Range

Tight competition characterizing automotive industries in the last decades has determined a strong research effort aimed to improve utilized processes and materials in sheet stamping. As far as the latter are regarded light weight alloys, high strength steels and tailored blanks have been increasingly utilized with the aim to reduce parts weight and fuel consumptions. In the paper the mechanical properties and formability of tailored welded blanks made of a precipitation hardenable aluminum alloy but with different sheet thicknesses, have been investigated: both laser welding and friction stir welding have been developed to obtain the tailored blanks. For both welding operations a wide range of the thickness ratios has been considered. The formability of the obtained blanks has been characterized through tensile tests and cup deep drawing tests, in order to show the formability in dependency of the stress condition; what is more mechanical and metallurgical investigations have been made on the welded joints.

Application of Quenching-Partitioning-Tempering Process in Hot Rolled Plate Fabrication

2010 ◽  
Vol 654-656 ◽  
pp. 82-85 ◽  
Author(s):  
Shu Zhou ◽  
Ying Wang ◽  
Nai Lu Chen ◽  
Yong Hua Rong ◽  
Jian Feng Gu
Keyword(s):  
Mechanical Properties ◽  
Retained Austenite ◽  
High Strength Steels ◽  
High Strength ◽  
Significant Fraction ◽  
Rolled Plate ◽  
Quenching And Partitioning ◽  
Good Ductility ◽  
Hot Rolled ◽  
Rolled Plates

The quenching-partitioning-tempering (Q-P-T) process, based on the quenching and partitioning (Q&P) treatment, has been proposed for producing high strength steels containing significant fraction of film-like retained austenite and controlled amount of fine martensite laths. In this study, a set of Q-P-T processes for C-Mn-Si-Ni-Nb hot rolled plates are designed and realized. The steels with Q-P-T processes present a combination of high strength and relatively good ductility. The origin of such mechanical properties is revealed by microstructure characterization.

The Role of Inclusions on Mechanical Properties in High Strength Steels

1972 ◽  
Vol 9 (6) ◽  
pp. 1339-1339 ◽  
Author(s):  
J. J. Hauser ◽  
M. G. H. Wells ◽  
I. Perlmutter
Keyword(s):  
Mechanical Properties ◽  
High Strength Steels ◽  
High Strength

scholarly journals Experimental Investigation on the Effect of Shot Peening and Deep Rolling on the Fatigue Response of High Strength Fasteners

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1093 ◽  
Author(s):  
Reggiani
Keyword(s):  
Fatigue Life ◽  
Shot Peening ◽  
High Strength Steels ◽  
High Strength ◽  
Experimental Tests ◽  
Published Data ◽  
Deep Rolling ◽  
Beneficial Impact ◽  
The Impact ◽  
Fatigue Life Enhancement

Shot-peening and deep rolling are mechanical surface treatments that are commonly applied to enhance the fatigue performances of components, owing to their capacity to generate compressive residual stresses and induce work hardening. However, literature is still poor of published data concerning the application of these treatments to high strength steels fasteners, although these represent a class of components among the most widespread. In the present work, the impact of deep rolling and shot-peening performed in the underhead radius of two set of fasteners made of 36NiCrMo and 42CrMoV for fatigue life enhancement has been investigated. The experimental tests consisted of six combinations of shot-peening and deep rolling, including the non-treated state. Two test campaigns have been sequentially carried out with different process parameters and treatment sequences. The results always showed a beneficial impact of the deep rolling on fatigue, especially for the 42CrMoV steel. Conversely, the effect of the shot-peening strongly depended on the selected set of parameters, alternatively leading to an improvement or a worsening of the fatigue life in relation to the level of induced surface roughness.

Relationship between Microstructure and Mechanical Properties in Q&P-Steels

2016 ◽  
Vol 879 ◽  
pp. 1933-1938 ◽  
Author(s):  
Richard G. Thiessen ◽  
Georg Paul ◽  
Roland Sebald
Keyword(s):  
Mechanical Properties ◽  
Dual Phase Steel ◽  
High Strength Steels ◽  
High Strength ◽  
The Body ◽  
Advanced High Strength Steels ◽  
Passenger Safety ◽  
Back Scattering ◽  
Body In White ◽  
Expected Increase

Third-Generation advanced high strength steels are being developed with the goal of reducing the body-in-white weight while simultaneously increasing passenger safety. This requires not only the expected increase in strength and elongation, but also improved local formability. Optimizing elongation and formability were often contradictory goals in dual-phase steel developments. Recent results have shown that so-called "quench and partitioning" (Q&P) concepts can satisfy both requirements [1]. Many Q&P-concepts have been studied at thyssenkrupp Steel Europe. Thorough investigation of the microstructure has revealed relationships between features such as the amount, morphology and chemical stability of the retained austenite and the obtained mechanical properties. An evaluation of the lattice strain by means of electron-back-scattering-diffraction has also yielded a correlation to the obtained formability. The aim of this work is to present the interconnection between these microstructural features and propose hypotheses for the explanation of how these features influence the macroscopically observed properties.

scholarly journals Microstructural characterization and mechanical properties of spot welded dissimilar advanced high strength steels

2021 ◽  
Author(s):  
Muhammad Sohaib Khan
Keyword(s):  
Mechanical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Microstructural Characterization ◽  
Advanced High Strength Steels ◽  
Spot Welded

Microstructural characterization and mechanical properties of spot welded dissimilar advanced high strength steels

scholarly journals Mechanical Properties of Heat Affected Zone of High Strength Steels

2015 ◽  
Vol 96 ◽  
pp. 012053 ◽  
Author(s):  
K Sefcikova ◽  
T Brtnik ◽  
J Dolejs ◽  
K Keltamaki ◽  
R Topilla
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
High Strength Steels ◽  
High Strength

High-Strength Steels Produced by Advanced Metallurgical Processes

1988 ◽  
Vol 4 (03) ◽  
pp. 169-185
Author(s):  
I. L. Stern ◽  
M. Wheatcroft ◽  
D. Y. Ku ◽  
R. F. Waite ◽  
W. Hanzalek
Keyword(s):  
Mechanical Properties ◽  
Heat Input ◽  
High Strength Steels ◽  
High Strength ◽  
Marine Industry ◽  
Metallurgical Processes ◽  
Strength And Toughness

Advanced metallurgical processes have made possible the manufacture of steels that—in addition to possessing high strength and toughness characteristics—maintain modest carbon equivalents for good weldabiiity results. These steels show promise of application in the marine industry because of their potential relative insensitivity to heat input and hardening and their potential for reduced requirements for preheat. This paper reviews several candidate steels, their composition, metallurgy and mechanical properties, and analyzes the results of a series of weldabiiity and toughness tests.

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