scholarly journals The Effects of Electrochemical Hydrogen Charging on Room-Temperature Tensile Properties of T92/TP316H Dissimilar Weldments in Quenched-and-Tempered and Thermally-Aged Conditions

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 864 ◽  
Author(s):  
Peter Ševc ◽  
Ladislav Falat ◽  
Lucia Čiripová ◽  
Miroslav Džupon ◽  
Marek Vojtko
Keyword(s):  
Hydrogen Embrittlement ◽  
Weld Metal ◽  
Tensile Properties ◽  
Thermal Aging ◽  
Room Temperature ◽  
Dominant Role ◽  
Type Ii ◽  
Plastic Properties ◽  
Hydrogen Charging ◽  
Material State

The influence of isothermal aging at 620 °C in combination with subsequent electrochemical hydrogen charging at room-temperature was studied on quenched-and-tempered T92/TP316H martensitic/austenitic weldments in terms of their room-temperature tensile properties and fracture behavior. Hydrogen charging of the weldments did not significantly affect their strength properties; however, it resulted in considerable deterioration of their plastic properties along with significant impact on their fracture characteristics and failure localization. The hydrogen embrittlement plays a dominant role in degradation of the plastic properties of the weldments already in their initial material state, i.e., before thermal aging. After thermal aging and subsequent hydrogen charging, mutual superposition of thermal and hydrogen embrittlement phenomena had led to clearly observable effects on the welds deformation and fracture processes. The measure of hydrogen embrittlement was clearly lowered for thermally aged material state, since the contribution of thermal embrittlement to overall degradation of the weldments has dominated. The majority of failures of the weldments after hydrogen charging occurred in the vicinity of T92 BM/Ni weld metal (WM) fusion zone; mostly along the Type-II boundary in Ni-based weld metal. Thus, regardless of aging exposure, the most critical failure regions of the investigated weldments after hydrogen charging and tensile straining at room temperature are the T92 BM/Ni WM fusion boundary and Type-II boundary acting like preferential microstructural sites for hydrogen embrittling effects accumulation.

scholarly journals Ageing Effects on Room-Temperature Tensile Properties and Fracture Behavior of Quenched and Tempered T92/TP316H Dissimilar Welded Joints with Ni-Based Weld Metal

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 791 ◽  
Author(s):  
Lucia Čiripová ◽  
Ladislav Falat ◽  
Peter Ševc ◽  
Marek Vojtko ◽  
Miroslav Džupon
Keyword(s):  
Weld Metal ◽  
Tensile Properties ◽  
Welded Joints ◽  
Room Temperature ◽  
Thermal Exposure ◽  
Tensile Tests ◽  
Strength Properties ◽  
Air Cooling ◽  
Plastic Properties ◽  
Ageing Effects

The present work is focused on the investigation of isothermal ageing effects on room-temperature tensile properties and the failure of quenched and tempered martensitic/austenitic weldments between T92 and TP316H heat-resistant steels. The dissimilar weldments were produced by gas tungsten arc welding technique using a Ni-based Thermanit Nicro 82 filler metal. The welded joints were subjected to unconventional post-welding heat treatment consisting of the welds solutionizing (1060 °C/30 min), followed by their water quenching and final stabilization tempering (760 °C/60 min). The treatment was completed by spontaneous air cooling within a tempering furnace. The welds in their initial quenched and tempered condition were subsequently aged at 620 °C for up to 2500 h. Apart from room-temperature tensile tests performed for all the welds material states, additional cross-weld hardness measurements were carried out on longitudinal sections of broken tensile specimens. The applied thermal exposure resulted in recognizable deterioration of plastic properties, whereas their effects on strength properties were rather small. The welds tensile straining and fracture evolution exhibited competitive behavior between the austenitic TP316H region and Ni-based weld metal. The observed failure locations showed significant hardness peaks due to intensive, necking-related strain hardening effects occurred during the tensile tests.

Thermal Aging Effects on Microstructures of Type-II Boundary in Dissimilar Metal Weld Joints

2014 ◽  
Author(s):  
Seung Chang Yoo ◽  
Kyoung Joon Choi ◽  
Ji Hyun Kim
Keyword(s):  
Heat Treatment ◽  
Weld Metal ◽  
Thermal Aging ◽  
Chromium Content ◽  
Boundary Region ◽  
Nanoindentation Test ◽  
Type Ii ◽  
Aging Effects ◽  
Fusion Boundary ◽  
Narrow Zone

In order to investigate the long-term thermal aging effects on the type-II boundary region in Alloy 152 weld metal, a representative dissimilar weld mock-up made of Alloy 690–Alloy 152–A533 Gr. B has been fabricated and heat treated under accelerated temperature conditions. To simulate the thermal aging effects, the heat treatment was performed at 450°C for 15, 30 and 60-yr equivalent times (1,375, 2,750 and 5,500 h). The aging time was determined by the diffusion equation based on the activation energy for chromium diffusion. The microstructure characterization was primarily conducted in the type-II boundary region of the weld root, which is a boundary parallel to fusion boundary existing within 100um from the fusion boundary and is known to be less resistant to stress corrosion cracking than other regions in the weld. The investigations were performed by scanning electron microscope, electron backscatter diffraction, and nanoindentation test. In this study, the dilution zone of the chromium content was observed at the weld metal region within a 1.5-mm range from the fusion boundary. Ferrites and high angle grain boundaries are found at the type-II boundary region of weld metal. In the narrow zone between the type-II boundary and fusion boundary, the hardness is relatively higher than that of other regions. These results show that the chromium content in the dilution zone increases with heat treatment, but the stiff chemical gradient still exists in the weld region at the narrow zone between the type-II boundary and fusion boundary.

Effect of thermal aging on the room temperature tensile properties of AISI type 316LN stainless steel

1999 ◽  
Vol 264 (1-2) ◽  
pp. 29-34 ◽  
Author(s):  
P Shankar ◽  
H Shaikh ◽  
S Sivakumar ◽  
S Venugopal ◽  
D Sundararaman ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Tensile Properties ◽  
Thermal Aging ◽  
Room Temperature ◽  
316Ln Stainless Steel ◽  
Aisi Type ◽  
Type 316Ln Stainless Steel

Microstructures and Tensile Properties of Fe-40Al Intermetallic with High Boron Content

2006 ◽  
Vol 510-511 ◽  
pp. 350-353
Author(s):  
Jin Hwan Lee ◽  
Jai Won Byeon ◽  
S.I. Kwun ◽  
S.J. Hong ◽  
J.G. Huh ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrogen Embrittlement ◽  
Strain Rate ◽  
Tensile Properties ◽  
Room Temperature ◽  
Boron Content ◽  
Tensile Elongation ◽  
High Boron ◽  
Scanning Electron

The effects of B addition up to 0.4 wt% (i.e., 1.61 at%) to Fe-40Al alloy on microstructures and tensile properties were investigated. The vacancy-annealed specimens following casting and extrusion were examined by optical and scanning electron microscopy and thermal neutron-induced microradiography. The addition of a large amount of B resulted in grain refinement and changed the fracture mode from intergranular to transgranular to increase the tensile elongation. Especially, the alloy containing 0.3wt% B exhibited the elongation of 16.4% under the strain rate of 1x100s-1 at room temperature. The increase in elongation with increasing strain rate was discussed in terms of suppression of hydrogen embrittlement.

Elevated Temperature Tensile Properties of Weld-Deposited Austenitic Stainless Steels

1976 ◽  
Vol 98 (3) ◽  
pp. 213-220
Author(s):  
A. L. Ward ◽  
L. D. Blackburn
Keyword(s):  
Elevated Temperature ◽  
Weld Metal ◽  
Tensile Properties ◽  
Stainless Steels ◽  
Room Temperature ◽  
Austenitic Stainless Steels ◽  
Metal Alloys ◽  
Elevated Temperature Tensile ◽  
Complex Features ◽  
Type 304

Trend curves describing the temperature dependence of tensile properties have been formulated for several weld-deposited austenitic stainless steels and also for wrought Type 304. Ratios of elevated-temperature properties to room-temperature properties were fitted to polynomial expressions in temperature by regression analysis. Represented in the study were eleven weldments, four weld processes, and five weld metal alloys. Trend curves were established for 308/308L, CRE 308, and 16-8-2 compositions as well as for all the weld metal data. The results showed that the degree of correlation between predicted and observed properties was dependent upon variations in weld process and parameters but that the ratio trend curve approach yielded a useful degree of correlation of the elevated-temperature properties even without considering all the complex features of the weld-deposited materials.

Hydrogen Embrittlement Behavior of the Amorphous Alloy Fe32Ni36Cr14P12B6

CORROSION ◽  
1982 ◽  
Vol 38 (9) ◽  
pp. 464-467 ◽  
Author(s):  
H. S. Tong ◽  
J. E. Macur
Keyword(s):  
Hydrogen Embrittlement ◽  
Amorphous Alloy ◽  
Current Density ◽  
Fracture Stress ◽  
Room Temperature ◽  
Fracture Morphology ◽  
Extension Rate ◽  
H2so4 Solution ◽  
Hydrogen Charging ◽  
A Current

Abstract Room temperature hydrogen embrittlement behavior of the amorphous alloy Fe32Ni36Cr14P12B6 was studied under various conditions. Hydrogen charging was performed in a 1N H2SO4 solution at a current density of 10 mA/cm2 and hydrogen embrittlement susceptibility was determined using the constant extension rate technique at an extension rate of 5.0×10−4 cm/S. The fracture stress decreased significantly on the hydrogenized specimen. However, recovery of this fracture stress was observed as a function of degassing time at room temperature. The fracture morphology of the specimens with/without hydrogen charging was also studied.

Hydrogen embrittlement of Ni–Ti superelastic alloy aged at room temperature after hydrogen charging

2007 ◽  
Vol 466 (1-2) ◽  
pp. 106-113 ◽  
Author(s):  
Ken’ichi Yokoyama ◽  
Toshio Ogawa ◽  
Katsutoshi Takashima ◽  
Kenzo Asaoka ◽  
Jun’ichi Sakai
Keyword(s):  
Hydrogen Embrittlement ◽  
Room Temperature ◽  
Hydrogen Charging

Effect of the Electro-Chemical Hydrogen Charging Time on Hydrogen Embrittlement of X70 Steel Using for Gas Pipeline

2013 ◽  
Vol 51 (11) ◽  
pp. 813-820
Author(s):  
Chi-Eun Sung ◽  
Hyeon-Jee Jeon ◽  
Jin-Kyung Lee ◽  
In-Soo Son ◽  
Sang-Pill Lee ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Gas Pipeline ◽  
Hydrogen Charging ◽  
Charging Time

Investigation of the V4+-Centre in 6H- and 4H-SIC by the Method of Spectral-Hole Burning

1998 ◽  
Vol 512 ◽  
Author(s):  
C. Hecht ◽  
R. Kummer ◽  
A. Winnacker
Keyword(s):  
Electronic Properties ◽  
Room Temperature ◽  
Hole Burning ◽  
Band Offset ◽  
Spectral Hole Burning ◽  
Type Ii ◽  
Thermally Stable ◽  
Spectral Hole

ABSTRACTIn the context of spectral-hole burning experiments in 4H- and 6H-SiC doped with vanadium the energy positions of the V4+/5+ level in both polytypes were determined in order to resolve discrepancies in literature. From these numbers the band offset of 6H/4H-SiC is calculated by using the Langer-Heinrich rule, and found to be of staggered type II. Furthermore the experiments show that thermally stable electronic traps exist in both polytypes at room temperature and considerably above, which may result in longtime transient shifts of electronic properties.

NIMROD 617KS

Alloy Digest ◽  
2002 ◽  
Vol 51 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Weld Metal ◽  
Tensile Properties ◽  
Base Metal ◽  
Heat Treating ◽  
Nominal Composition

Abstract Nimrod 617KS is an Inconel-type consumable with a nominal composition of nickel, 24% Cr,12% Co, and 9% Mo and is used to join UNS N06617 and Nicrofer 6023 to themselves. The alloy is designed for high-temperature service and is often used as the weld metal in dissimilar cases to ensure the weld is as strong as the base metal. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on heat treating and joining. Filing Code: Ni-583. Producer or source: Metrode Products Ltd.

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