scholarly journals AN INVESTIGATION OF METALLURGICAL FACTORS WHICH AFFECT THE FRACTURE TOUGHNESS OF ULTRA HIGH STRENGTH STEELS

1973 ◽  
Author(s):  
William E. Wood ◽  
Earl R. Parker ◽  
Victor F. Zackay
Keyword(s):  
Fracture Toughness ◽  
High Strength Steels ◽  
High Strength ◽  
Ultra High Strength Steels

Characterization of Tempered 4340 Steel after 1200°C Austenitization

1980 ◽  
Vol 38 ◽  
pp. 380-381
Author(s):  
K. P. Datta ◽  
V. C. Kannan
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Yield Strength ◽  
High Strength Steels ◽  
High Strength ◽  
Subsequent Tempering ◽  
Considerable Research ◽  
4340 Steel ◽  
Ultra High Strength Steels

Considerable research is in progress to improve the fracture toughness of low alloy ultra-high strength steels such as 4340 while maintaining the same level of yield strength. One such methodis high temperature austenitization (1200° C). Subsequent tempering, in general, renders still higher toughness and hence this study is aimed at characterization of tempered 4340 steel after 1200° C austenitization.

Sulfide Stability, Void Nucleation and the Toughness of Ultra High Strength Steels

1990 ◽  
Vol 186 ◽  
Author(s):  
W. M. Garrison ◽  
J. L. Maloney
Keyword(s):  
Fracture Toughness ◽  
Volume Fraction ◽  
Void Nucleation ◽  
High Strength Steels ◽  
High Strength ◽  
Calcium Sulfide ◽  
Chromium Sulfide ◽  
Ultra High Strength Steels ◽  
Inclusion Volume ◽  
Inclusion Volume Fraction

The upper shelf fracture toughness of ultra high strength steels is dependent on both the microstructure, which is determined by composition and heat treatment, and on the inclusions present in the steel. The inclusions In ultra high strength steels are typically oxides and sulfides [1]. In most ultra high strength steels the sulfides are manganese sulfides, although depending on the composition of the steel and the melt practice used, other sulfides are found, such as chromium sulfide, calcium sulfide and lanthanum oxy-sulfide [2]. If the inclusions can be regarded as pre-existing voids then the inclusion volume fraction and spacing appear to be sufficient to characterize the inclusion population from the standpoint of fracture toughness [3,4]. The purpose of this paper is to discuss results which show sulfur can be gettered as particles which are much more resistant to void nucleation than manganese sulfides and that this increased resistance to void nucleation can result in vastly improved upper shelf fracture toughness. In particular, when HY180 steel contains manganese sulfides the fracture toughness is about 250 MPa but when the sulfur is gettered as particles containing titanium, carbon and sulfur the fracture toughness of HY180 steel will approach 550 MPa . These particles, believed to be titanium carbosulfides, are much more resistant to void nucleation than manganese sulfides and this increased resistance to void nucleation appears to be the reason for the improved fracture toughness.

scholarly journals Fracture toughness of hydrogen charged as-quenched ultra-high-strength steels at low temperatures

2017 ◽  
Vol 688 ◽  
pp. 190-201 ◽  
Author(s):  
Sakari Pallaspuro ◽  
Haiyang Yu ◽  
Anna Kisko ◽  
David Porter ◽  
Zhiliang Zhang
Keyword(s):  
Fracture Toughness ◽  
Low Temperatures ◽  
High Strength Steels ◽  
High Strength ◽  
Ultra High Strength Steels

Applicability of the Master Curve Method to Ultra High Strength Steels

2015 ◽  
Author(s):  
Kim Wallin ◽  
Sakari Pallaspuro ◽  
Päivi Karjalainen-Roikonen ◽  
Pasi Suikkanen
Keyword(s):  
Fracture Toughness ◽  
Brittle Fracture ◽  
Size Effect ◽  
Temperature Dependence ◽  
Master Curve ◽  
High Strength Steels ◽  
High Strength ◽  
Master Curve Method ◽  
Curve Method ◽  
Ultra High Strength Steels

Although Ultra High Strength Steels (UHSS) with nominal strengths up to 1500 MPa have been available on the market for many years, the use of these steels in the civil engineering industry is still rather uncommon. One critical point limiting the use of UHSS steels lies in their rather poorly documented fracture properties in relation to more conventional steels covered by the codes. The major concept governing the assessment of steels is the Master Curve (MC) methodology. It provides a description for the fracture toughness scatter, size effect and temperature dependence in the ductile to brittle transition region. It enables a complete characterization of brittle fracture toughness of a material based on only a few small size specimens. The method combines a theoretical description of the scatter, a statistical size effect and an empirically found temperature dependence of fracture toughness. The fracture toughness in the brittle fracture regime is thus described with only one parameter, the transition temperature T0. At this temperature the mean fracture toughness for a 25.4 mm thick specimen is 100 MPa√m. The Master Curve method as defined in ASTM E1921-13a is applicable to ferritic structural steels with yield strength between 275 MPa and 825 MPa. Very few studies have been made with respect to the applicability of the Master Curve to Ultra High Strength Steels with yield strengths in the excess of 900 MPa. This is the topic of this work. Focusing on novel directly quenched high performance steels, the applicability of the Master Curve methodology with special emphasis on the temperature dependence will be investigated. Possible improvements to the Master Curve will be proposed for further consideration.

scholarly journals Untempered Ultra-high Strength Steels of High Fracture Toughness

1972 ◽  
Vol 236 (68) ◽  
pp. 108-109 ◽  
Author(s):  
V. F. ZACKAY ◽  
E. R. PARKER ◽  
R. D. GOOLSBY ◽  
W. E. WOOD
Keyword(s):  
Fracture Toughness ◽  
High Strength Steels ◽  
High Strength ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Ultra High Strength Steels

BETHLEHEM LUKENS PLATE SPARTAN

Alloy Digest ◽  
2003 ◽  
Vol 52 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Tensile Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Tensile Yield Strength ◽  
Precipitation Reactions

Abstract Bethlehem Lukens Plate (BLP) offers five grades of Spartan high-strength steels with tensile yield strength over 690 MPa (100 ksi). These alloys contain copper for precipitation reactions. They also have improved weldability and toughness compared to ASTM A 514 and A 543 grades. This datasheet provides information on composition, microstructure, hardness, and tensile properties as well as fracture toughness. It also includes information on forming and joining. Filing Code: SA-518. Producer or source: Bethlehem Lukens Plate.

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