scholarly journals Effect of Carbon Content and Other Variables on Yield Strength, Ductility and Creep Properties of Alloy 625

1994 ◽  
Author(s):  
U. Heubner ◽  
M. Kohler
Keyword(s):  
Yield Strength ◽  
Carbon Content ◽  
Creep Properties ◽  
Alloy 625

scholarly journals Characterization of Microstructure in High-Hardness Surface Layer of Low-Carbon Steel

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 995
Author(s):  
Haitao Xiao ◽  
Shaobo Zheng ◽  
Yan Xin ◽  
Jiali Xu ◽  
Ke Han ◽  
...  
Keyword(s):  
Surface Layer ◽  
Carbon Steel ◽  
Yield Strength ◽  
Carbon Content ◽  
Acicular Ferrite ◽  
Lath Martensite ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Upper Bainite ◽  
Mixed Microstructure

Surface hardening improves the strength of low-carbon steel without interfering with the toughness of its core. In this study, we focused on the microstructure in the surface layer (0–200 μm) of our low-carbon steel, where we discovered an unexpectedly high level of hardness. We confirmed the presence of not only upper bainite and acicular ferrite but also lath martensite in the hard surface layer. In area of 0–50 μm, a mixed microstructure of lath martensite and B1 upper bainite was formed as a result of high cooling rate (about 50–100 K/s). In area of 50–200 μm, a mixed microstructure of acicular ferrite and B2 upper bainite was formed. The average nanohardness of the martensite was as high as 9.87 ± 0.51 GPa, which was equivalent to the level reported for steel with twenty times the carbon content. The ultrafine laths with an average width of 128 nm was considered to be a key cause of high nanohardness. The average nanohardness of the ferrites was much lower than for martensite: 4.18 ± 0.39 GPa for upper bainite and 2.93 ± 0.30 GPa for acicular ferrite. Yield strength, likewise, was much higher for martensite (2378 ± 123 MPa) than for upper bainite (1007 ± 94 MPa) or acicular ferrite (706 ± 72 MPa). The high yield strength value of martensite gave the surface layer an exceptional resistance to abrasion to a degree that would be unachievable without additional heat treatment in other steels with similar carbon content.

Recovery of Creep Properties of Alloy 625 After Long Term Service

1999 ◽  
Vol 171-174 ◽  
pp. 537-544 ◽  
Author(s):  
M.D. Mathew ◽  
K. Bhanu Sankara Rao ◽  
S.L. Mannan ◽  
K. Paknikar ◽  
Ranbir Singh
Keyword(s):  
Creep Properties ◽  
Alloy 625

Creep properties of service-exposed Alloy 625 after re-solution annealing treatment

2004 ◽  
Vol 372 (1-2) ◽  
pp. 327-333 ◽  
Author(s):  
M.D. Mathew ◽  
K. Bhanu Sankara Rao ◽  
S.L. Mannan
Keyword(s):  
Annealing Treatment ◽  
Solution Annealing ◽  
Creep Properties ◽  
Alloy 625

Correlation between microstructure and yield strength of as-quenched and Q&P steels with different carbon content (0.06–0.42 wt%C)

2019 ◽  
Vol 753 ◽  
pp. 1-10 ◽  
Author(s):  
Guhui Gao ◽  
Bo Gao ◽  
Xiaolu Gui ◽  
Jie Hu ◽  
Jianzhong He ◽  
...  
Keyword(s):  
Yield Strength ◽  
Carbon Content

scholarly journals CREEP PROPERTIES AND PREDICTION MODEL OF PADDY SOIL UNDER COMPRESSION

2021 ◽  
pp. 441-451
Author(s):  
Guoyang Liu ◽  
Junfang Xia ◽  
Kan Zheng ◽  
Jian Cheng ◽  
Liu Jiang ◽  
...  
Keyword(s):  
Yield Strength ◽  
Nonlinear Model ◽  
Paddy Soil ◽  
Soil Tillage ◽  
Coefficient Of Determination ◽  
Creep Properties ◽  
Plastic Model ◽  
Burgers Model ◽  
Nonlinear Viscoelastic ◽  
Deformation Properties

In order to study the compressive creep properties and laws of paddy soil, multi-stress creep experiments of paddy soil with different moisture content were carried out. The results show that the creep deformation of paddy soil, subjected to compressive loads effect, develops stably and the paddy soil is not destructed under the yield strength when the stress is low. When the stress level is higher than the yield strength, the internal damage of paddy soil would be caused at the moment of loading. With the extension of creep time, the cracks would gradually expand, resulting in the soil to yield, break and disintegrate. According to the analysis of the deformation properties of paddy soil under compression and the change trend of creep curve, the nonlinear viscoelastic-plastic model was composed of the nonlinear viscoplastic model and Burgers model in series. The creep test curve was introduced into the model for fitting, and the coefficient of determination reached more than 0.96. Based on the model, the strain composition, strain proportion, and strain rate of paddy soil were studied. Finally, the nonlinear model was compared with Burgers model by verification test. The fitting accuracy of the nonlinear model was better than Burgers model, and the coefficient of determination and relative error were 0.997 and 0.437%, respectively, which proved the rationality and correctness of the nonlinear viscoelastic-plastic model. This study can provide a theoretical basis for the optimization of tillage machinery structure and the simulation analysis of soil tillage and compaction.

Welding of Internally Clad X65 Pipes With Precipitation Strengthened Ni-Based Filler Metals

2017 ◽  
Author(s):  
Graciela C. Penso ◽  
Boian T. Alexandrov
Keyword(s):  
Yield Strength ◽  
Weld Metal ◽  
Parameter Optimization ◽  
Filler Metal ◽  
Gas Metal Arc Welding ◽  
Welding Parameter ◽  
Cold Metal Transfer ◽  
Alloy 625 ◽  
Metal Yield ◽  
Cold Metal

X65 steel pipes internally clad with Alloy 625 used in subsea oil extraction are normally welded together with Alloy 625 filler metal. For pipe reeling applications, DNV-OS-F101 requires pipe girth welds to overmatch base metal yield strength with 100 MPa. Since Alloy 625 filler metal does not meet this requirement, Ni-base super alloys 718 and 282 were considered as potential welding consumables for reeling applications. The solidification behavior in weld metal of these alloys diluted with Alloy 625 pipe ID cladding was evaluated using thermodynamic simulations. The response to precipitation hardening by multiple reheat cycles was studied by producing multilayer buildups with cold metal transfer (CMT) and pulsed gas metal arc welding (GMAWp) processes. Weld buildup of Alloy 718 exhibited insufficient hardening response and yield strength, while Alloy 282 met the DNV overmatch requirement. Successful narrow groove welding of X65 pipes with Alloy 282 was performed using CMT process. Welding parameter optimization allowed resolving centerline solidification cracking and lack of fusion defects. The weld metal yield strength was lower than in the multipass buildup, which was attributed to lower number of reheats in groove welding. Meeting the overmatch requirement for yield strength in Alloy 282 groove welds requires further parameter optimization.

Bleaching ability of pre-hydrolyzed pulps in the context of a biorefinery mill

TAPPI Journal ◽  
2013 ◽  
Vol 12 (11) ◽  
pp. 49-53 ◽  
Author(s):  
CHRISTINE CHIRAT ◽  
LUCIE BOIRON ◽  
DOMINIQUE LACHENAL
Keyword(s):  
Carbon Content ◽  
Acid Hydrolysis ◽  
13C Nmr ◽  
Kraft Lignin ◽  
Kappa Number ◽  
Hydroxyl Groups ◽  
Kraft Pulps ◽  
Quaternary Carbon ◽  
Oxygen Delignification

Autohydrolysis and acid hydrolysis treatments were applied on mixed softwood chips. The cooking ability was studied by varying the alkali and duration of the cook. Pulps with kappa numbers varying from 30 to 70 were obtained. The bleaching ability of these pulps was studied and compared to control kraft pulps. The prehydrolyzed pulps were shown to be more efficiently delignified by oxygen than the control kraft pulps starting from the same kappa number. Furthermore, the final bleaching was also easier for these pulps. It was also shown that extensive oxygen delignification applied on high-kappa pre-hydrolyzed pulps could be a way to improve the overall yield, which is a prerequisite for the development of such biorefinery concepts. Lignin was isolated from the control kraft and the two pre-hydrolyzed kraft pulps and analyzed by 13C NMR. Lignins from pre-hydrolyzed kraft pulps had similar free phenolic groups content to the control kraft lignin, but their aliphatic hydroxyl groups and β-O-4 content were lower than for the control lignin. The quaternary carbon content was the same for all the samples.

Evaluation of an Alternate Method for Determining Yield Strength Offset Values for Selective Laser Sintered Polymeric Materials

2019 ◽  
Author(s):  
Chelsey Henry ◽  
Keith Rupel ◽  
Charles Park ◽  
Joseph Costanzo ◽  
Cary Kaczowka ◽  
...  
Keyword(s):  
Yield Strength ◽  
Polymeric Materials
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