On microstructural and mechanical properties of 21-4-N nitronic steel joint developed using microwave energy

2021 ◽  
pp. 251659842110334
Author(s):  
Shivani Bhandari ◽  
Shivani Gupta ◽  
Radha Raman Mishra ◽  
Apurbba Kumar Sharma ◽  
Navneet Arora
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Base Metal ◽  
Nickel Powder ◽  
Weld Zone ◽  
Microwave Energy ◽  
Complete Fusion ◽  
Carbide Phases ◽  
Microwave Applicator ◽  
Heating Mode

In the current experimental work, an effort has been made to explore the feasibility of fusion joints of 21-4-N nitronic steel employing microwave heating. These fusion joints were developed inside a domestic microwave applicator operating at 900 W. Microwave energy was used to fabricate the joints in hybrid heating mode by converting electromagnetic energy into heat at 2.45 GHz. Charcoal and SiC plates were used as susceptor and separator, respectively, and nickel powder was used as the interface material. The developed joints were characterized for their microstructural and mechanical properties. The microstructures indicate a complete fusion of nickel interfacing powder with the faying surfaces. XRD results show the formation of metallic nitrides and carbide phases (Cr2N, Fe3N, and Fe2C) and the FeNi phase at the weld zone. Furthermore, the observed average tensile strength of the fusion joints was approximately 61% of base metal. The reduction in the stress and elongation compared to the base metal were 38.67% and 12.68%, respectively. The average microhardness of the microwave joints was monitored as 407 ± 69.27 HV. The results indicate the feasibility of fusion joints of nitronic steel using microwave energy.

Tensile Strength of Forged Ti-6Al-4V Welded Joints by Electronic Beam Welding

2011 ◽  
Vol 255-260 ◽  
pp. 132-136
Author(s):  
Hong Yu Qi ◽  
Jian Xie ◽  
Dong Pan ◽  
Shao Lin Li ◽  
Xiao Guang Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Base Metal ◽  
Welded Joints ◽  
Empirical Relationship ◽  
Weld Zone ◽  
Structure Design ◽  
Microstructure And Mechanical Properties ◽  
Welded Structure ◽  
Static Tensile

Forged Ti-6Al-4V welded structure by electronic beam welding (EBW) as integrally bladed disk (blisk) structure in advanced aero-engine has been widely applied. It is necessary to analyze microstructure and mechanical properties of Ti-6Al-4V welded joints by EBW for failure analysis and structure design of blisk. Firstly the microstructure and mechanical properties of forged Ti-6Al-4V welded joints was focused on. Grains in the weld zone become coarse and large gradient organization structure appears in the heat affected zone (HAZ), which presents significant local heterogeneity. Microhardness of the weld zone is about 20% higher than that of the base metal. The size of different region of the welded joints was estimated. Then static tensile test of three different specimens were carried on. Experiment results show that the tensile and yield strength of welded joints are not less than that of the base metal. Finally the empirical relationship between strength and hardness of Ti-6Al-4V alloy is established. Tensile strength of the weld zone and the base metal were estimated. Compared to experiment data, the deviation is 3.56%, 0.097% respectively.

scholarly journals Microstructures and Mechanical Properties of a Laser-Welded Joint of Ti3Al-Nb Alloy Using Pure Nb Filler Metal

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 785 ◽  
Author(s):  
Lin Wang ◽  
Daqian Sun ◽  
Hongmei Li ◽  
Xiaoyan Gu ◽  
Chengjie Shen
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Base Metal ◽  
Joint Strength ◽  
Filler Metal ◽  
Weld Zone ◽  
Strengthening Effect ◽  
Joint Properties ◽  
Microstructures And Mechanical Properties ◽  
Welding System

Ti3Al-Nb alloy (Ti-24Al-15Nb) was welded by a pulsed laser welding system without and with pure Nb filler metal. The results indicated that pure Nb filler metal had profound effects on the microstructures and mechanical properties of the laser-welded joints. The joint without filler metal consisted of the weld zone (α’2 + B2), heat affected zone HAZ1 (α2 + B2), HAZ2 (α2 + O + B2) and base metal (α2 + O + B2), and gas pores were generated in the weld resulting in the deterioration of the joint strength (330 MPa) and elongation (1.9%). When the Nb filler metal was used, the weld microstructure (NbTi solid solution + O + B2) was obtained, and the joint properties were significantly improved, which was associated with the strengthening effect of the NbTi solid solution, O phase precipitation and the slip transmission between O and B2 phases, and the restraining of the formation of martensite (α’2) and gas pores in the weld. The strength (724 MPa) and elongation (5.1%) of the joint increased by 119.4% and 168.4% compared with those of the joint without filler metal, and the joint strength was able to reach 81.7% of the base metal strength (886 MPa). It is favorable to use pure Nb filler metal for improving the mechanical properties of laser-welded Ti3Al-Nb alloy joints.

An Investigation into Microstructures and Properties of 7075-T6 during Friction Stir Welding

2013 ◽  
Vol 772 ◽  
pp. 94-97 ◽  
Author(s):  
Wei Wu ◽  
Da Jun Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Weld Zone ◽  
Base Metals ◽  
Rotating Speed ◽  
Friction Stir ◽  
Strain Fracture ◽  
Ductile Mode ◽  
Equiaxed Grains

Microstructural and mechanical properties of friction stir welded 4mm7075-T6 aluminum alloy were investigated in this paper. The microstructures in WAZ,TMAZ and HAZ were analyzed. The results show that with the rotating speed at 1500 rpm and welding speed at 60mm/min, a defect-free welding joint was obtained. The tensile strength was 362 MPa, which is 65% of base metals; Weld nugget is composed of equiaxed grains; The lowest hardness between the TMAZ and HAZ of advancing side. The fractography revealed that samples failed in ductile mode and the strain fracture appears in advancing side of weld zone.

scholarly journals Optimizing the Integrity of Linear Friction Welded Ti2AlNb Alloys

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 802
Author(s):  
Xi Chen ◽  
Zhao Zhang ◽  
Faqin Xie ◽  
Xiangqing Wu ◽  
Tiejun Ma ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Process Parameters ◽  
Precipitation Hardening ◽  
Weld Zone ◽  
Aging Treatment ◽  
Weld Interface ◽  
Welding Parameters ◽  
Linear Friction ◽  
O Phase

The knowledge of process parameters–weld integrity-aging treatments–tensile property relationship is of great concern for linear friction welded (LFWed) Ti2AlNb-based alloy and requires a systematic characterization. Thus, the Ti2AlNb-based alloy was LFWed under various process parameters and then subjected to different aging treatments. Twelve welding conditions were used to evaluate the weld integrity, showing that impurities and cracks at weld interface can be eliminated under strong welding parameters and the feed rate has the greatest influence on the weld integrity among all process parameters. Relationships among aging temperatures, microstructure evolution, and mechanical properties were investigated. After aging treatment, acicular O phase has precipitated in B2 grains both in the weld zone and thermo-mechanical affected zone (TMAZ). The size of precipitated O phase increases along with the increase of temperature, and the α2 +·O mixtures have finally decomposed into the aggregated acicular O phase. The microhardness and tensile strength of the joints have been enhanced due to the precipitation hardening of O phase and refined grain strengthening after aging treatments.

Enhanced Mechanical Properties of AA5083 GTA Weldments with Current Pulsing and Addition of Scandium

2013 ◽  
Vol 765 ◽  
pp. 716-720 ◽  
Author(s):  
N. Kishore Babu ◽  
Patil Yogesh Bhikanrao ◽  
K. Sivaprasad
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fusion Zone ◽  
Weld Zone ◽  
Solidification Structure ◽  
Grain Structure ◽  
Welding Parameters ◽  
Pulsed Current ◽  
Current Technique ◽  
Aa5083 Alloy

AA5083 alloy is welded with gas tungsten arc welding using optimized welding parameters. Al-Si-Sc master alloy filler with varying contents of scandium is used for welding. Welding was carried out with and without AC-pulsed current techniques. A narrow heat affected zone with more refined grain structure is observed in the case of the pulsed current technique. Furthermore, it is observed that the columnar solidification structure in the fusion zone was suppressed and fine equiaxed grains were formed in the weld zone with increasing scandium content, which is attributed to the grain refinement effect of scandium with the generation of increased nucleating sites during weld solidification. This effect is reflected in mechanical properties also. An increased hardness of about 10 % results with pulsed current technique compared to about 20 % with an addition of 0.75 % scandium. However, in the case of tensile properties pulsing resulted in about 8 % increase in tensile strength and addition of 0.75 % scandium resulted in about 40 % increase in tensile strength. Both the pulsed current technique and the addition of scandium were observed to be better in increasing not only strength but also elongation due to the refined grain structure in the weld fusion zone.

scholarly journals Effect of Reversed Austenite on Mechanical Properties of ZG06Cr13Ni4Mo Repair Welded Joint

Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Yunhai Su ◽  
Zuyong Wei ◽  
Gang Li ◽  
Xiangwen Zhang ◽  
Hedi Ci ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Base Metal ◽  
Welded Joints ◽  
Welded Joint ◽  
Lath Martensite ◽  
Optical Microscope ◽  
Reversed Austenite ◽  
Repair Welding ◽  
Gas Tungsten Arc

In this work, gas tungsten arc welding (GTAW) was used to repair ZG06Cr13Ni4Mo martensitic stainless steel. Repair welding occurred either once or twice. The changes in the microstructure and properties of the repair welded joints were characterized by optical microscope (OM), scanning electron microscope (SEM), electron backscattering diffraction (EBSD), tensile and impact tests. The effects of reversed austenite in repair welded joints on microstructure and mechanical properties were studied. The results show that the microstructure of the welded joint after repair welding consists of a large amount of martensite (M) and a small amount of reversed austenite (A), and the reversed austenite is distributed at the boundary of martensite lath in fine strips. With the increase in the number of welding repairs, the content of reversed austenite in the welded joint increases. The microstructure in the repair welded joints is gradually refined, the microstructure in the once and twice repaired joints is 45.2% and 65.1% finer than that in the casting base metal, respectively. The reversed austenite presented in the repair welded joints decreases the tensile strength by 4.8% and 6.7%, increases the yield strength by 21.3% and 26.4%, and increases the elongation by 25% and 56%, respectively, compared with the casting base metal. In addition, the reversed austenite mainly nucleates and grows at the boundary of lath martensite. The refinement of the martensite structure was due to the generation of reversed austenite and the refinement of original austenite grain by the welding thermal cycle. After repair welding, the reverse austenite appeared in the repair welded joints and the tensile strength decreased slightly, but the plastic toughness was significantly improved, which was conducive to the subsequent service process.

scholarly journals Repair Welding of the Tunnel Defect in Friction Stir Weld

2018 ◽  
Vol 37 (7) ◽  
pp. 675-681 ◽  
Author(s):  
Weipo Li ◽  
Zhimin Liang ◽  
Congwei Cai ◽  
Dianlong Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Weld Zone ◽  
Welding Process ◽  
Friction Stir Weld ◽  
Strength Increase ◽  
Repair Welding ◽  
Friction Stir ◽  
Longitudinal Residual Stress

AbstractThe tunnel defect formed in friction stir weld would dramatically push the mechanical properties of joints into deterioration. In this study, friction stir welding process was adopted to repair the joints of 7N01 aluminum alloy with tunnel defect. The effects of friction stir repair welding process on the microstructure and mechanical properties were comprehensively investigated. Microstructure of the repaired joints shows that the grain size in nugget zone decreases slightly while the recrystallization in the retreating side of thermo-mechanically affected zone is intensified as the joints are repaired. The microhardness of the repaired joints declined slightly compared with the defective joint. However, the yield strength and tensile strength increase and recover to the values of the joints free of defect. The longitudinal residual stress in weld zone increased remarkably as the repair times increase. Compared with the once repaired joint, yield strength and tensile strength of the twice repaired joint reduced slightly, and the throat thickness also reduced during the repeated repair welding process. Therefore, the times of repair welding applied should be limited actually.

scholarly journals Microstructure and Mechanical Properties of Gas Tungsten Arc Welded High Manganese Steel Sheet

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1167 ◽  
Author(s):  
Geon-Woo Park ◽  
Haeju Jo ◽  
Minha Park ◽  
Sunmi Shin ◽  
Won-Seok Ko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Base Metal ◽  
Steel Sheet ◽  
Weld Zone ◽  
Manganese Steel ◽  
High Manganese ◽  
High Manganese Steel ◽  
Gas Tungsten Arc ◽  
Microstructure And Mechanical Properties

This study investigated microstructure and mechanical properties of high manganese steel sheet fabricated by gas tungsten arc welding (GTAW). The weld zone showed longitudinal coarse grains due to the coalescence of columnar dendrites grown into the direction of heat source, and the HAZ showed equiaxed coarser grains than the base metal due to the thermal effect of GTAW process. Mn segregation occurred in the inter-dendritic regions of the weld zone and Mn depletion thus occurred in the weld matrix. Although the stacking fault energy is expected to be lowered due to the Mn depletion, no noticeable change in the initial phase and deformation mechanism was found in the weld matrix. Lower hardness and strength were shown in the weld zone than the base metal, which was caused by the coarser grain size. The negative strain rate sensitivity observed in the weld zone and the base metal is considered to have originated from the negative strain rate dependency of twinning nucleation stress.

Influence of Hot Working Conditions on Mechanical Properties and Microstructures at Weld Zone of the Ti3Al /TC4 Dual Alloy

2010 ◽  
Vol 97-101 ◽  
pp. 140-144
Author(s):  
Ze Kun Yao ◽  
Chun Qin ◽  
Hong Zhen Guo ◽  
Jing Xia Cao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Working Conditions ◽  
Room Temperature ◽  
Weld Zone ◽  
Hot Working ◽  
Affecting Factors ◽  
Comprehensive Properties ◽  
Temperature Heat Treatment

The influences of different hot working conditions on the microstructures and mechanical properties at weld zone of the Ti3Al/TC4 dual alloy have been investigated. The experimental results show that forging and heat treatment has significant influence on room temperature tensile strength (RTTS for short) of the weld zone. The influence of forging strain and temperature on its elongation at temperature 500°C is also conspicuous. The results of intuitional and variance analysis show that affecting factors of its RTTS are heat treatment, forging strain, forge temperature and condition of billet in sequence. The affecting factors of its room temperature (RT for short) ductility and the tensile strength (TS for short) at temperature 500 °C are forging strain, forge temperature, heat treatment and condition of billet. Good comprehensive properties are obtained under optimal conditions: forging at 1020°C, annealing at 700°C for 12 hours, air cooled, about 40% strain and as-rolled billet. The microstructures of the weld zone worked according as those conditions are uniform and the grain size is also fine.

Experimental Investigation of Welding Parameters on Automatic TIG Welding of Aluminium 5083 Plate

2016 ◽  
Vol 879 ◽  
pp. 1459-1464
Author(s):  
V.V. Praveen ◽  
T.D. John ◽  
K.M. Peethambaran
Keyword(s):  
Tensile Strength ◽  
Base Metal ◽  
Welding Speed ◽  
Weld Zone ◽  
Specific Effect ◽  
Tig Welding ◽  
Weld Strength ◽  
Welding Parameters ◽  
Width Ratio ◽  
Utility Concept

To improve the weld quality of AA 5083 plate using AA 5356 filler rod, an automatic TIG welding system is developed, by which welding speed can be controlled and a uniform speed is obtained. Welding of aluminium 5083 plate is carried out for different welding currents and welding speeds. In this work, the effect of welding speed and current on, the tensile strength of the weld, hardness at the three different zones viz. weld metal, HAZ and base metal are investigated. The temperature is measured at the HAZ and base metal. The hardness and temperature on the weld zone and the base metal are greatly influenced by the welding speed and current. It is found that the weld strength is influenced by different values of weld current and speed, but sometimes with high current, welding speed has no specific effect on the tensile strength of the weld. The effect of material deposition rate on the weld strength in uniform welding is studied. The weld thickness to width ratio is an important aspect in the analysis of weld strength. The values obtained for current and speed are taken for optimizing the strength and hardness, using Taguchi method and utility concept.

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