The Effect of Heat Treatment on the Room Temperature and Elevated Temperature Fracture Toughness Response of Alloy 718

1980 ◽  
Vol 102 (1) ◽  
pp. 118-126 ◽  
Author(s):  
W. J. Mills
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Fracture Resistance ◽  
Room Temperature ◽  
Alloy 718 ◽  
High Temperature Solution ◽  
Temperature Solution ◽  
Temperature Fracture ◽  
Conventional Material ◽  
Test Temperature Range

The effect of heat treatment on the JIC fracture toughness behavior of Alloy 718 was characterized at room temperature, 427°C and 538°C. Two different heat treatments were used: the conventional (ASTM A637) treatment, and a modified heat treatment designed to improve the toughness of Alloy 718 base metal and weldments. The elastic-plastic JIC fracture toughness response of the modified Alloy 718 was found to be superior to the JIC behavior exhibited by the conventional material over the entire test temperature range. Metallographic and fractographic examinations of Alloy 718 fracture surfaces revealed that the inferior fracture resistance of the conventional superalloy was attributed to the presence of coarse δ precipitates throughout the conventional matrix. The increased fracture toughness response of the modified Alloy 718 was related to the dissolution of coarse δ precipitates during the high temperature solution anneal employed in the modified treatment.

Improvement of room temperature fracture toughness in Cr2Nb-based alloys by heat treatment

2014 ◽  
Vol 31 (1) ◽  
pp. 59-62
Author(s):  
K. W. Li ◽  
S. M. Li ◽  
X. B. Wang ◽  
H. Zhong ◽  
Y. L. Xue ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Room Temperature ◽  
Temperature Fracture

CHROMIUM COPPER-999

Alloy Digest ◽  
1953 ◽  
Vol 2 (8) ◽  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Low Temperature ◽  
Physical Properties ◽  
Heat Treating ◽  
High Temperature Solution ◽  
Temperature Solution ◽  
Precipitation Heat

Abstract Chromium Copper-999 is a copper-chromium-silicon alloy which is softened by a high-temperature solution anneal and quench, and will acquire improved properties with a low-temperature precipitation heat treatment. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness and creep. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: Cu-10. Producer or source: American Brass Company.

Microstructural Evolution and Room Temperature Fracture Toughness of a Nb-Ti-Si-Cr-Al-Hf-Y Alloy Prepared by Directional Solidification

2019 ◽  
Vol 971 ◽  
pp. 59-64
Author(s):  
Guan Qun Zhuo ◽  
Lin Fen Su ◽  
Kai Yong Jiang
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Directional Solidification ◽  
Microstructural Evolution ◽  
Room Temperature ◽  
Growth Direction ◽  
Withdrawal Rate ◽  
The Matrix ◽  
Temperature Fracture

The Nb-24Ti-12Si-14Cr-2Al-2Hf-0.1Y (at.%) alloys were fabricated by directional solidification with selected withdrawal rate 1.2 and 18 mm/min, followed by a heat treatment at 1375 °C for 10 h. The microstructure of directional solidified samples were composed of NbSS, Cr2Nb and eutectics (NbSS+Nb5Si3), aligning with the growth direction. After heat treatment, the NbSS in the eutectic structures and NbSS dendrites were connected to form the matrix, and the silicide and Cr2Nb tended to spheroidize. The sample prepared by higher withdrawal rate plus heat treament shows higher average KQ values. The results suggested that the Nb-Si based alloy showed higher room-temperature fracture toughness when the microstructure consists of continuous NbSS distributed with finer Nb5Si3 and Cr2Nb.

scholarly journals Effect of Microstructural Continuity on Room-Temperature Fracture Toughness of ZrC-Added Mo–Si–B Alloys

2018 ◽  
Vol 59 (4) ◽  
pp. 518-527 ◽  
Author(s):  
Shunichi Nakayama ◽  
Nobuaki Sekido ◽  
Sojiro Uemura ◽  
Sadahiro Tsurekawa ◽  
Kyosuke Yoshimi
Keyword(s):  
Fracture Toughness ◽  
Room Temperature ◽  
Temperature Fracture

Improvement of Low Temperature Fracture Toughness of AIST 403 Stainless Steel by Microalloying and Heat Treatment

1997 ◽  
Vol 16 (2) ◽  
pp. 149-157 ◽  
Author(s):  
G. Gupta, ◽  
S. Wadekar, ◽  
J.S. Dubey, ◽  
R.T. Savalia, ◽  
K.S. Balakrishnan, ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Stainless Steel ◽  
Low Temperature ◽  
Temperature Fracture

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.

The Room Temperature and Elevated Temperature Fracture Toughness Response of Alloy A-286

1978 ◽  
Vol 100 (2) ◽  
pp. 195-199 ◽  
Author(s):  
W. J. Mills
Keyword(s):  
Fracture Toughness ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Second Phase ◽  
Surface Micromorphology ◽  
Second Phase Particles ◽  
The Matrix ◽  
Temperature Fracture ◽  
Increasing Temperature ◽  
Base Superalloy

The elastic-plastic fracture toughness (JIc) response of precipitation strengthened Alloy A-286 has been evaluated by the multi-specimen R-curve technique at room temperature, 700 K (800°F) and 811 K (1000°F). The fracture toughness of this iron-base superalloy was found to decrease with increasing temperature. This phenomenon was attributed to a reduction in the materials’s strength and ductility at elevated temperatures. Electron fractographic examination revealed that the overall fracture surface micromorphology, a duplex dimple structure coupled with stringer troughs, was independent of test temperature. In addition, the fracture resistance of Alloy A-286 was found to be weakened by the presence of a nonuniform distribution of second phase particles throughout the matrix.

Temperature Dependence of Fracture Toughness of the Cubic (L12) Titanium Trialuminides

1996 ◽  
Vol 460 ◽  
Author(s):  
R. A. Varin ◽  
L. Zbroniec
Keyword(s):  
Fracture Toughness ◽  
Stress Intensity Factor ◽  
Room Temperature ◽  
Maximum Load ◽  
Gradual Transition ◽  
Transgranular Cleavage ◽  
Temperature Range ◽  
Temperature Fracture ◽  
Increasing Temperature ◽  
Work Of Fracture

ABSTRACTFracture toughness vs. temperature of the cubic (L12), Mn- modified titanium trialuminide (based on Al3Ti) was investigated in air at the temperature range up to 1000°C. Toughness calculated from the maximum load exhibits a broad peak (KQ≈7–10 MPara0,5) at the 200- 500°C temperature range and then decreases with increasing temperature, reaching a room temperature value of ∼4.5 MPam0.5 at 1000°C. However, the work of fracture (γWOF, J/m2) and the stress intensity factor calculated from it (KIWOF) increases continuously with increasing temperature. Fracture modes exhibit a gradual transition from transgranular cleavage at room temperature to predominantly intergranular failure at the 800- 1000°C range.

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