Effect of Welding Method on the Hardness of Joint of 600MPa Grade New Generation Steel

2012 ◽  
Vol 538-541 ◽  
pp. 1526-1531
Author(s):  
Zhi Jun Huang ◽  
Lun Ji Hu ◽  
Tao Pen ◽  
Yu Tao Wang ◽  
Jia He
Keyword(s):  
Weld Metal ◽  
High Efficiency ◽  
Welded Joint ◽  
Fusion Line ◽  
Peak Hardness ◽  
Hybrid Welding ◽  
Softening Effect ◽  
New Generation ◽  
Softened Zone ◽  
Grade Steel

Laser-MAG hybrid, GMAW and SAW welding experiment were carried out for the new low CE 600MPa grade steel, and hardness survey on the welded joints was performed. Laser-MAG hybrid welding has the highest speed with the least filling weld metal, and its joint exhibits almost no softening with higher harness in weld than base metal. SAW welding has high efficiency but most significant softening effect on the HAZ. For SAW, on the HAZ 4 ~ 5 mm apart from the fusion line peak hardness exists. For GMAW, on the HAZ about 2mm away from the fusion line a softened zone appears, but the softening degree is lower than for SAW. The results showed that the hardness of the welded joint of this type of steel seems much subjected to the welding heat input.

Effect of Heat Input on Structure and Mechanical Properties of Low Matched Welded Joint in a 1000MPa Grade Steel

2011 ◽  
Vol 418-420 ◽  
pp. 1184-1187 ◽  
Author(s):  
Zheng Jun Liu ◽  
Chu Ao Wang ◽  
Yun Hai Su ◽  
Fu Dong Zhao ◽  
Le Cheng Li
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Heat Input ◽  
Welded Joint ◽  
Optical Microscope ◽  
Metallurgical Structure ◽  
Weld Metal Microstructure ◽  
Optimal Values ◽  
Metal Microstructure ◽  
Grade Steel

In order to investigate the effect of heat input on the microstructure and mechanical properties of low matched high-tensile steel welded joint, the metallurgical structure and mechanical properties of welded joint obtained with different heat input were analyzed using optical microscope , welded joint tensile test and impact test of weld metal. The results show that the optimal values are obtained when the heat input is 11.9KJ/cm,where the tensile strength is 798.45MPa and ballistic work is 69J; Weld metal microstructure is mainly composed by the primary ferrite and acicular ferrite. The width of the dendrite and grain size of the weld metal microstructure increase with the increasing of the heat input.

Analysis of Porosity Characteristics in Weld Metal of High Strength Aluminum Alloy and the Effect of Mixed Shielding Gas

2005 ◽  
Vol 475-479 ◽  
pp. 309-312 ◽  
Author(s):  
Xiao Mu Zhang ◽  
Zhi Yong Zhang ◽  
Yun Peng ◽  
Zhi Ling Tian ◽  
Chang Hong He ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Weld Metal ◽  
Welded Joint ◽  
High Strength ◽  
Mig Welding ◽  
Shielding Gas ◽  
Mixed Gas ◽  
Porosity Formation ◽  
High Strength Aluminum Alloy ◽  
Softened Zone

Aluminum alloy has being widely used in modern automobile and aeronautic industry. However, the welding of aluminum alloy, especially high strength aluminum alloy，is difficult. Porosities are usually brought in the weld metal. In this paper, MIG welding using mixed gas shielding is carried out. The characteristic shapes of porosity in weld metal are described, the mechanism of porosity formation is analyzed, and the factors that influence the tendency of porosity formation are studied. Experiment results indicate that by the use of mixed shielding gas of 38%He+62%Ar, the number of porosity is reduced, the width of HAZ and softened zone is decreased, and the mechanical properties of welded joint is increased.

scholarly journals Recent Advancements in Polythiophene-Based Materials and Their Biomedical, Geno Sensor and DNA Detection

2021 ◽  
Vol 22 (13) ◽  
pp. 6850
Author(s):  
Seyyed Mojtaba Mousavi ◽  
Seyyed Alireza Hashemi ◽  
Sonia Bahrani ◽  
Khadije Yousefi ◽  
Gity Behbudi ◽  
...  
Keyword(s):  
Biomedical Engineering ◽  
High Efficiency ◽  
Polymeric Materials ◽  
The Novel ◽  
Electrode Coating ◽  
Effective Response ◽  
Hiv Drugs ◽  
New Generation ◽  
New Compounds ◽  
Anti Hiv

In this review, the unique properties of intrinsically conducting polymer (ICP) in biomedical engineering fields are summarized. Polythiophene and its valuable derivatives are known as potent materials that can broadly be applied in biosensors, DNA, and gene delivery applications. Moreover, this material plays a basic role in curing and promoting anti-HIV drugs. Some of the thiophene’s derivatives were chosen for different experiments and investigations to study their behavior and effects while binding with different materials and establishing new compounds. Many methods were considered for electrode coating and the conversion of thiophene to different monomers to improve their functions and to use them for a new generation of novel medical usages. It is believed that polythiophenes and their derivatives can be used in the future as a substitute for many old-fashioned ways of creating chemical biosensors polymeric materials and also drugs with lower side effects yet having a more effective response. It can be noted that syncing biochemistry with biomedical engineering will lead to a new generation of science, especially one that involves high-efficiency polymers. Therefore, since polythiophene can be customized with many derivatives, some of the novel combinations are covered in this review.

scholarly journals The Bacterial Enzyme Cas13 Interferes with Neurite Outgrowth from Cultured Cortical Neurons

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 262
Author(s):  
Qin-Wei Wu ◽  
Josef P. Kapfhammer
Keyword(s):  
Rna Editing ◽  
Cortical Neurons ◽  
High Efficiency ◽  
Primary Cultures ◽  
Cultured Neurons ◽  
Therapeutic Tool ◽  
Bacterial Enzyme ◽  
Rna Targeting ◽  
Cultured Cortical Neurons ◽  
New Generation

The CRISPR-Cas13 system based on a bacterial enzyme has been explored as a powerful new method for RNA manipulation. Due to the high efficiency and specificity of RNA editing/interference achieved by this system, it is currently being developed as a new therapeutic tool for the treatment of neurological and other diseases. However, the safety of this new generation of RNA therapies is still unclear. In this study, we constructed a vector expressing CRISPR-Cas13 under a constitutive neuron-specific promoter. CRISPR-Cas13 from Leptotrichia wadei was expressed in primary cultures of mouse cortical neurons. We found that the presence of CRISPR-Cas13 impedes the development of cultured neurons. These results show a neurotoxic action of Cas13 and call for more studies to test for and possibly mitigate the toxic effects of Cas13 enzymes in order to improve CRISPR-Cas13-based tools for RNA targeting.

Cyclic Mechanical Properties of 16MnR Welded Joint under Constant

2011 ◽  
Vol 197-198 ◽  
pp. 1658-1661
Author(s):  
Ying Xiong ◽  
Han Ying Zheng
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Endurance Limit ◽  
Welded Joint ◽  
Cyclic Softening ◽  
Fatigue Tests ◽  
Test Results ◽  
Control Test ◽  
Strain Control ◽  
Fatigue Endurance

Fatigue tests are carried out for 16MnR welded joint under constant strain control. Test results reveal that 16MnR weld metal exhibits characteristic of cyclic softening and non-masing obviously. The strain–life curve can be best described by the three-parameter equation. It shows the fatigue endurance limit in the heat-affecting zone (HAZ) of welded joint is lower than that in the weld metal.

scholarly journals ANALISIS KEGAGALAN TABUNG GAS LPG KAPASITAS 3 KG

2018 ◽  
Vol 34 (1) ◽  
pp. 19
Author(s):  
Tarmizi
Keyword(s):  
Weld Metal ◽  
Fusion Line ◽  
Burn Through

Penelitian ini dilakukan untuk mengetahui penyebab dari kebocoran tabung gas LPG kapasitas 3 kg yang terjadi di daerah lasan (circumferensial welding). Untuk itu dilakukan pengkajian kualitas dan performance di daerah lasan pada badan tabung secara metalurgi, dengan melakukan pengujian komposisi kimia, pengujian mekanik yaitu: uji tarik, uji bending, uji kekerasan, dan metallografi. Sifat mekanik dari tabung pada dasamya dipengaruhi oleh komposisi kimia dan struktur mikro. Dari hasil uji komposisi kimia, badan tabung mempunyai nilai CE < 0,40%, sehingga mempunyai kemampuan untuk dilas. Tetapi nilai sensitivitas retaknya (Pem) mendekati nilai kritis (2,3%) sehingga nilai kekuatan tarik dan keuletannya pada sambungan las relatif turun yang menyebabkan adanya retakan dari hasil uji bending. Perbedaan perubahan nilai kekerasan rata-rata yang sangat besar yaitu dengan adanya kenaikan antara weld metal dengan fusion line sebesar 11,60% (25,11 HV) dan terjadi penurunan antara fusion line dengan HAZ sebesar 0,56% (1,21 HV). Perbedaan yang sangat besar inilah yang memicu terjadinya retak saat pengujian bending padaface bend, dimana lokasi retakan ada di fusion line. Kebocoran yang terjadi di daerah lasan (circumferensial welding) disebabkan oleh penipisan dinding tabung akibat proses joggling sehingga pada saat pengelasan arus yang digunakan akan terlalu besar yang akan menyebabkan terjadinya cacat burn through di daerah akar las, sehingga mengubah dimensi ketebalan dinding tabung yaitu dengan adanya cacat yang menyerupai takikan. Hal ini merupakan inisiasi terjadinya retak yang merambat menembus dinding tabung sehingga terjadi kebocoran.

Industrial Sewing Machine Design and Development of Digital Design and Simulation Platform

2013 ◽  
Vol 365-366 ◽  
pp. 917-920
Author(s):  
De Fa Zhang ◽  
Yi Cong Gao
Keyword(s):  
Energy Saving ◽  
High Performance ◽  
High Efficiency ◽  
Machine Intelligence ◽  
Digital Design ◽  
Machine Design ◽  
Design And Development ◽  
Sewing Machine ◽  
Great Leap Forward ◽  
New Generation

In recent years, industrial sewing machine intelligence can be increased. Compared with the traditional equipment, the new generation of domestic equipment in the "high efficiency, energy saving, special" has realized great-leap-forward development. In the performance, will towards high precision, high efficiency, high performance, intelligent direction; in function, to the miniaturization, multi-function direction; in the program, to the systematic, integrated direction. The design and development of industrial sewing machine digitization design packaging platform are discussed.

scholarly journals Efficiency Evaluation of the Ejector Cooling Cycle using a New Generation of HFO/HCFO Refrigerant as a R134a Replacement

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2136 ◽  
Author(s):  
Bartosz Gil ◽  
Jacek Kasperski
Keyword(s):  
High Efficiency ◽  
Coefficient Of Performance ◽  
Condensation Temperature ◽  
Evaporation And Condensation ◽  
Wide Range ◽  
Theoretical Investigations ◽  
Maximum Coefficient ◽  
C 30 ◽  
New Generation ◽  
And Control

Theoretical investigations of the ejector refrigeration system using hydrofluoroolefins (HFOs) and hydrochlorofluoroolefin (HCFO) refrigerants are presented and discussed. A comparative study for eight olefins and R134a as the reference fluid was made on the basis of a one-dimensional model. To facilitate and extend the possibility of comparing our results, three different levels of evaporation and condensation temperature were adopted. The generator temperature for each refrigerant was changed in the range from 60 °C to the critical temperature for a given substance. The performed analysis shown that hydrofluoroolefins obtain a high efficiency of the ejector system at low primary vapor temperatures. For the three analyzed sets of evaporation and condensation temperatures (te and tc equal to 0 °C/25 °C, 6 °C/30 °C, and 9 °C/40 °C) the maximum Coefficient of Performance (COP) was 0.35, 0.365, and 0.22, respectively. The best performance was received for HFO-1243zf and HFO-1234ze(E). However, they do not allow operation in a wide range of generator temperatures, and, therefore, it is necessary to correctly select and control the operating parameters of the ejector.

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