scholarly journals The Effect of Electrolytic Hydrogenation on Mechanical Properties of T92 Steel Weldments under Different PWHT Conditions

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3653 ◽  
Author(s):  
Lucia Čiripová ◽  
Ladislav Falat ◽  
Viera Homolová ◽  
Miroslav Džupon ◽  
Róbert Džunda ◽  
...  
Keyword(s):  
Transformation Temperature ◽  
Arc Welding ◽  
Room Temperature ◽  
Tensile Tests ◽  
Air Cooling ◽  
Short Term ◽  
Gas Tungsten Arc ◽  
Electrolytic Hydrogen ◽  
Electrolytic Hydrogenation ◽  
The Individual

In the present work, the effects of electrolytic hydrogen charging of T92 steel weldments on their room-temperature tensile properties were investigated. Two circumferential weldments between the T92 grade tubes were produced by gas tungsten arc welding using the matching Thermanit MTS 616 filler material. The produced weldments were individually subjected to considerably differing post-welding heat treatment (PWHT) procedures. The first-produced weldment was conventionally tempered (i.e., short-term annealed below the Ac1 critical transformation temperature of the T92 steel), whereas the second one was subjected to its full renormalization (i.e., appropriate reaustenitization well above the T92 steel Ac3 critical transformation temperature and subsequent air cooling), followed by its conventional subcritical tempering. From both weldments, cylindrical tensile specimens of cross-weld configuration were machined. The room-temperature tensile tests were performed for the individual welds’ PWHT states in both hydrogen-free and electrolytically hydrogen-charged conditions. The results indicated higher hydrogen embrittlement susceptibility for the renormalized-and-tempered weldments, compared to the conventionally tempered ones. The obtained findings were correlated with performed microstructural and fractographic observations.

Evaluation of Repair Welding Influence on GH3535 Superalloy Microstructure and Mechanical Properties

2016 ◽  
Author(s):  
Chaowen Li ◽  
Shuangjian Chen ◽  
Kun Yu ◽  
Zhijun Li
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Weld Seam ◽  
Filler Metal ◽  
Short Term ◽  
Weld Repair ◽  
Repair Welding ◽  
Gas Tungsten Arc ◽  
Rolled Plates ◽  
Carbide Precipitate

GH3535 supperalloy, whose grade of ASME is UNS N10003, is currently considered as a candidate material for solid-fuel and fluid-fuel molten salt reactor in china. During the development of procedures for welding GH3535 superalloy, consideration should always be given to the possibility that repair welding may be necessary. This paper presents weld repairs of GH3535 alloy rolled plates using gas tungsten arc welding with filler metal. The purpose of this work is to evaluate the low heat input process for weld repair of GH3535 alloy plates about the microstructure features and mechanical properties. The results demonstrated that sound joints without defects could be obtained after weld repairs. Due to repair thermal cycles on the original weld seam, the size of carbide precipitate became large, but repair welding is found to cause no decrease in short-term time-independent strength.

Microstructure Characteristics of Fe-xCr-C Hardfacing Alloys

2012 ◽  
Vol 472-475 ◽  
pp. 165-168
Author(s):  
Lin Zong ◽  
Zheng Jun Liu
Keyword(s):  
Solid Solution ◽  
Optical Microscopy ◽  
Arc Welding ◽  
Room Temperature ◽  
Gas Tungsten Arc Welding ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure Characteristics ◽  
Gas Tungsten Arc ◽  
Gtaw Process

A series of Fe-xCr-C hardfacing alloys were successfully fabricated on a substrate of 20g steel by gas tungsten arc welding (GTAW) process. These claddings were disigned to observe hypoeutectic, near-eutectic, and hypereutectic structures with various Cr3C2 and M7C3 carbides at room temperature. According to X-ray diffraction(XRD) and optical microscopy (OM), the hypoeutectic and eutectic composites include the Fe-Cr solid solution(α+A) and Cr3C2 carbides. Hypereutectic structures consist of α+A+M+M7C3 respectively. The cladding of hypereutectic microstructure with great amounts of primary M7C3 carbides had the highest hardness of the all conditions.

scholarly journals Strain Effect On Microstructural Properties Of SUS 304L Joint By PAW+GTAW

2021 ◽  
Author(s):  
Juan Wang ◽  
Yajiang Li ◽  
Qi Wang ◽  
Kun Liu ◽  
Hang Li
Keyword(s):  
Arc Welding ◽  
Room Temperature ◽  
Welded Joint ◽  
Welding Process ◽  
Strain Effect ◽  
304L Stainless Steel ◽  
Plasma Arc Welding ◽  
Microstructural Properties ◽  
Gas Tungsten Arc ◽  
Static Tensile

Abstract 304L stainless steel was joined by a combination welding process of plasma arc welding and gas tungsten arc welding (PAW + GTAW). Then pre-strain treatment on 304L welded joint by 9% was carried out using uniaxial static tensile at room temperature. Effect of strain on microstructure evolution in joint was analyzed by field emission scanning electron microscope (FESEM) and on mechanical properties was also studied. The results indicated that the strain rate of 304L joint showed inhomogeneity including 3% in the weld metal and 13% in the heat affected zone (HAZ), which induced martensitic transformation occurring in HAZ. Tensile strength of the joint increased from 700MPa as welded to 804MPa after strain at room temperature and it reached 1700MPa from 1480MPa at low temperature of -196℃. Impact toughness in HAZ was the least among the whole joint, but it was still 94J at -196℃after strain. The fracture surface showed large numbered of cleavage steps with elongated parabolic dimples.

scholarly journals Strain effect on microstructural properties of SUS 304L joint by PAW+GTAW

2021 ◽  
Author(s):  
Wang Juan ◽  
Li Yajiang ◽  
Wang Qi ◽  
Liu Kun ◽  
Li Hang
Keyword(s):  
Arc Welding ◽  
Room Temperature ◽  
Welded Joint ◽  
Welding Process ◽  
Fracture Morphology ◽  
Strain Effect ◽  
304L Stainless Steel ◽  
Plasma Arc Welding ◽  
Gas Tungsten Arc ◽  
Static Tensile

AbstractJIS SUS 304L stainless steel was joined by a combination welding process of plasma arc welding and gas tungsten arc welding (PAW+GTAW). Then pre-strain treatment on 304L welded joint of 9 % was carried out using uniaxial quasi-static tensile at room temperature. Effect of strain on microstructure evolution in joint was analyzed by field emission scanning electron microscope (FESEM) and on mechanical properties was also studied. The results indicated that the pre-strain rate of 304L joint showed inhomogeneity including 3 % in the weld metal and 13 % in the heat-affected zone (HAZ), which induced martensitic transformation occurring in HAZ. Tensile strength of the joint increased from 700 MPa as welded to 804 MPa after pre-strain treatment at room temperature, and it reached 1700 MPa from 1480 MPa as welded at low temperature of −196 °C. Impact energy in the HAZ was the least among the whole 304L weld, but it was still 94 J at −196 °C after pre-strain. The fracture morphology showed large numbered of cleavage steps with elongated parabolic dimples.

Microstructure and Mechanical Behavior of AISI 430 FSS Welds Produced with Different Elemental Metal Powder Addition

2019 ◽  
Vol 297 ◽  
pp. 195-203 ◽  
Author(s):  
Nabil Bensaid ◽  
Mohamed Hadji ◽  
Riad Badji ◽  
Mohamed Farid Benlamnouar ◽  
Taher Saadi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Tensile Tests ◽  
Gas Tungsten Arc ◽  
Powder Addition ◽  
Steel Welds ◽  
Equiaxed Grains ◽  
Metal Powder Addition ◽  
Aisi 430 ◽  
Scanning Electron

In this study the effect of the Titanium and aluminum powder addition on microstructure and mechanical properties of AISI 430 ferritic stainless steel welds produced by gas tungsten arc welding was investigated. It’s observed that the addition of aluminium (Al) or titanium (Ti) reducing the grains size, increase the equiaxed grains fraction and improve the mechanical properties with varying degrees. While the addition of mixture (Al+Ti) leads to better improving in mechanical properties and reducing of grains size up to 85 %. The details of tensile tests, optical microscopic observations, microhardness, tensile test and Scanning electron microscopy (SEM) fractography, are discussed.

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.

Determination of allostatic load dynamics in the assessment of adaptation in temporary workers in the Arctic

2020 ◽  
pp. 547-548
Author(s):  
O. Yu. Atkov ◽  
S. G. Gorokhova
Keyword(s):  
Body Mass Index ◽  
Glucose Level ◽  
Shift Work ◽  
Allostatic Load ◽  
The Arctic ◽  
Temporary Workers ◽  
Short Term ◽  
Short Term Adaptation ◽  
The Individual

The individual dynamics of the allostatic load index was revealed mainly due to changes in the glucose level, body mass index, which makes it applicable for assessing the short-term adaptation to the stay in the conditions of shift work

INCONEL FILLER METAL 52

Alloy Digest ◽  
1992 ◽  
Vol 41 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Arc Welding ◽  
Filler Metal ◽  
Pressurized Water Reactors ◽  
Pressurized Water ◽  
High Chromium ◽  
Inconel Alloy ◽  
Gas Tungsten Arc ◽  
Alloy 690 ◽  
Water Reactors

Abstract INCONEL FILLER METAL 52 is a high chromium filler metal for gas-metal-arc and gas-tungsten-arc welding of Inconel Alloy 690 (See Alloy Digest Ni-266, March 1981). Higher chromium is beneficial in resisting stress-corrosion cracking in high purity water for pressurized water reactors and for resistance to oxidizing acids. This datasheet provides information on composition and tensile properties. It also includes information on corrosion resistance as well as joining. Filing Code: Ni-412. Producer or source: Inco Alloys International Inc..

scholarly journals First experimental evidence of the piezoelectric nature of struvite

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jolanta Prywer ◽  
Rafał Kruszyński ◽  
Marcin Świątkowski ◽  
Andrzej Soszyński ◽  
Dariusz Kajewski ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Experimental Evidence ◽  
Heating Rate ◽  
Transformation Temperature ◽  
Room Temperature ◽  
Piezoelectric Coefficient ◽  
Piezoelectric Properties ◽  
Parallel Plates ◽  
Gel Growth ◽  
Growth Technique

AbstractIn this paper, we present the first experimental evidence of the piezoelectric nature of struvite (MgNH4PO4·6H2O). Using a single diffusion gel growth technique, we have grown struvite crystals in the form of plane parallel plates. For struvite crystals of this shape, we measured the piezoelectric coefficients d33 and d32. We have found that at room temperature the value of piezoelectric coefficient d33 is 3.5 pm/V, while that of d32 is 4.7 pm/V. These values are comparable with the values for other minerals. Struvite shows stable piezoelectric properties up to the temperature slightly above 350 K, for the heating rate of 0.4 K/min. For this heating rate, and above this temperature, the thermal decomposition of struvite begins, which, consequently, leads to its transformation into dittmarite with the same non-centrosymmetric symmetry as in case of struvite. The struvite-dittmarite transformation temperature is dependent on the heating rate. The higher the heating rate, the higher the temperature of this transformation. We have also shown that dittmarite, like struvite exhibits piezoelectric properties.

scholarly journals The effect of short-term storage temperature on the key headspace volatile compounds observed in Canadian faba bean flour

2021 ◽  
pp. 108201322199884
Author(s):  
Rami Akkad ◽  
Ereddad Kharraz ◽  
Jay Han ◽  
James D House ◽  
Jonathan M Curtis
Keyword(s):  
Fatty Acids ◽  
Volatile Compounds ◽  
Room Temperature ◽  
Unsaturated Fatty Acids ◽  
Solid Phase ◽  
Short Term ◽  
Bean Flour ◽  
Odour Activity Value ◽  
Short Term Storage ◽  
Term Storage

The odour emitted from the high-tannin fab bean flour ( Vicia faba var. minor), was characterized by headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC–MS). The relative odour activity value (ROAV) was used to monitor the changes in key volatile compounds in the flour during short-term storage at different temperature conditions. The key flavour compounds of freshly milled flour included hexanal, octanal, nonanal, decanal, 3-methylbutanal, phenyl acetaldehyde, (E)-2-nonenal, 1-hexanol, phenyl ethyl alcohol, 1-octen-3-ol, β-linalool, acetic acid, octanoic acid, and 3-methylbutyric acid; these are oxidative degradation products of unsaturated fatty acids and amino acids. Despite the low lipid content of faba beans, the abundances of aldehydes arising during room temperature storage greatly contributed to the flavour of the flour due to their very low odour thresholds. Two of the key volatiles responsible for beany flavour in flour (hexanal, nonanal) increased greatly after 2 weeks of storage at room temperature or under refrigerated conditions. These volatile oxidation products may arise as a result of enzymatic activity on unsaturated fatty acids, and was seen to be arrested by freezing the flour.

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