scholarly journals Pengaruh kondisi parameter pengelasan MAG sambungan las baja tidak sejenis terhadap struktur mikro dan kekerasan daerah HAZ

2021 ◽  
Vol 16 (3) ◽  
pp. 457
Author(s):  
Harlian Kadir ◽  
Riswanda Riswanda ◽  
Abdul Syukur Alfauzi ◽  
Bambang Sumiyarso
Keyword(s):  
Aisi 304L

Makalah ini difokuskan pada pengaruh kondisi parameter pengelasan MAG (<em>Metal Active Gas</em>) terhadap sifat kekerasan daerah HAZ, dan struktur mikro sambungan las baja tidak sejenis. Dalam industri Fabrikasi dan disain difokuskan pada kebutuhan untuk menggabungkan logam yang tidak sejenis, karena kebutuhan atau prasyarat Teknik baru disain yang kreatif dan sifat rancangan khusus.  Baja karbon rendah Hypoeutektoid (AISI 1015) dan baja tahan karat austentik (304L SS) dipilih dalam penelitian ini. Arus las digunakan dengan tiga variasi yang berbeda pada 120A, 130A dan 140A. Pengelasan MAG menggunakan kawat elektroda padat ER70S6, dengan diameter 1,2 mm. Identifikasi struktur makro di daerah terpengaruh panas (HAZ) dan kekerasan mikro <em>vickers</em> dan pengujian tarik dilakukan untuk setiap spesimen hasil las. Struktur makro sambungan las yang berbeda menunjukkan hasil pada variasi arus las 120A, kualitas sambungan las dan penetrasi lebih baik, jika dibandingkan dengan yang menggunakan arus las 130A dan 140A yang memiliki penetrasi berlebihan. Hasil kekerasan mikro <em>vickers </em>pada logam las lebih tinggi jika dibandingkan dengan logam induk dan baja hypoeutektoid (AISI 1015) dan baja tahan karat austenitik  AISI 304L, dan kekerasan <em>vickers</em> pada logam las juga lebih tinggi karena pengaruh elektroda kawat padat ER70S6 yang digunakan. Haisl pengujian kekuatan tarik dan kekuatan luluh sambungan las MAG  meningkat pada 120A dan 140A, dan patahan terjadi ada pada baja hipo euctektoid (AISI 1015) dibatas antara daerah yang terpengaruh panas dan logam induk. Dari penelitian ini didapatkan bahwa sambungan las MAG dengan arus las 120A lebih baik digunakan untuk penyambungan logam tidak sejenis antara baja karbon rendah (AISI 1015) dan baja tahan karat austenitik (AISI 304L).

scholarly journals Influence of Activated Fluxes on the Bead Shape of A-TIG Welds on Carbon and Low-Alloy Steels in Comparison with Stainless Steel AISI 304L

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 530
Author(s):  
Jerzy Niagaj
Keyword(s):  
Stainless Steel ◽  
Penetration Depth ◽  
High Strength ◽  
Tig Welding ◽  
Low Alloy Steels ◽  
Aisi 304L ◽  
A Tig Welding ◽  
Alloy Steels ◽  
Steel Aisi ◽  
Stainless Steel Aisi

The article presents results of comparative A-TIG welding tests involving selected unalloyed and fine-grained steels, as well as high-strength steel WELDOX 1300 and austenitic stainless steel AISI 304L. The tests involved the use of single ingredient activated fluxes (Cr2O3, TiO2, SiO2, Fe2O3, NaF, and AlF3). In cases of carbon and low-alloy steels, the tests revealed that the greatest increase in penetration depth was observed in the steels which had been well deoxidized and purified during their production in steelworks. The tests revealed that among the activated fluxes, the TiO2 and SiO2 oxides always led to an increase in penetration depth during A-TIG welding, regardless of the type and grade of steel. The degree of the aforesaid increase was restricted within the range of 30% to more than 200%.

Optimizing Pulsed Current Micro Plasma Arc Welding Parameters to Maximize Ultimate Tensile Strength of AISI 304L Sheets Using Response Surface Method

2014 ◽  
Vol 660 ◽  
pp. 322-326
Author(s):  
Kondapalli Siva Prasad ◽  
Chalamalasetti Srinivasa Rao ◽  
Damera Nageswara Rao
Keyword(s):  
Mathematical Model ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Response Surface ◽  
Response Surface Method ◽  
Welding Parameters ◽  
Pulsed Current ◽  
Plasma Arc ◽  
Aisi 304L ◽  
Surface Method

AISI 304L is an austenitic Chromium-Nickel stainless steel offering the optimum combination of corrosion resistance, strength and ductility. These attributes make it a favorite for many mechanical components. The paper focuses on developing mathematical model to predict ultimate tensile strength of pulsed current micro plasma arc welded AISI 304L joints. Four factors, five level, central composite rotatable design matrix is used to optimize the number of experiments. The mathematical model has been developed by response surface method. The adequacy of the model is checked by ANOVA technique. By using the developed mathematical model, ultimate tensile strength of the joints can be predicted with 99% confidence level. Contour plots are drawn to study the interaction effect of pulsed current micro plasma arc welding parameters ultimate tensile strength of AISI 304L steel. The developed mathematical model has been optimized using Response Surface Method to maximize the ultimate tensile strength.

scholarly journals Finite Element Analysis of the Magnetic Field Distribution in a Magnetic Abrasive Finishing Station and its Impact on the Effects of Finishing Stainless Steel AISI 304L

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 194
Author(s):  
Michał Marczak ◽  
Józef Zawora
Keyword(s):  
Finite Element ◽  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Flux Density ◽  
Regression Equations ◽  
Element Analysis ◽  
Aisi 304L ◽  
Magnetic Abrasive Finishing ◽  
The Real ◽  
Abrasive Finishing

In this article, we present a numerical model of a magnetic abrasive finishing station, which was analyzed using the finite element method (FEM). The obtained results were compared with the real values measured on an experimental station of our own design. The prepared station had the option of adjusting the magnetic flux density inside the machining gap, the width of which could be changed from 10 to 30 mm. The maximum value of the magnetic flux density inside the air gap was 0.8 T. The real distribution of magnetic flux density in the finishing area was also analyzed. A design of experiment was carried out with the following variables: abrasive grain concentration, width of the machining gap, and process duration. The results are presented in the form of regression equations and characteristics for selected roughness parameters.

scholarly journals Stacking Fault Energy in Relation to Hydrogen Environment Embrittlement of Metastable Austenitic Stainless CrNi-Steels

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1170
Author(s):  
Robert Fussik ◽  
Gero Egels ◽  
Werner Theisen ◽  
Sebastian Weber
Keyword(s):  
Phase Transformation ◽  
Intermediate Stage ◽  
Tensile Tests ◽  
Stacking Fault ◽  
Hydrogen Gas ◽  
Stacking Fault Energy ◽  
Austenitic Steels ◽  
Aisi 304L ◽  
Hydrogen Environment ◽  
Gas Atmosphere

Metastable austenitic steels react to plastic deformation with a thermally and/or mechanically induced martensitic phase transformation. The martensitic transformation to α’-martensite can take place directly or indirectly via the intermediate stage of ε-martensite from the single-phase austenite. This effect is influenced by the stacking fault energy (SFE) of austenitic steels. An SFE < 20 mJ/m2 is known to promote indirect conversion, while an SFE > 20 mJ/m2 promotes the direct conversion of austenite into α’-martensite. This relationship has thus far not been considered in relation to the hydrogen environment embrittlement (HEE) of metastable austenitic CrNi steels. To gain new insights into HEE under consideration of the SFE and martensite formation of metastable CrNi steels, tensile tests were carried out in this study at room temperature in an air environment and in a hydrogen gas atmosphere with a pressure of p = 10 MPa. These tests were conducted on a conventionally produced alloy AISI 304L and a laboratory-scale modification of this alloy. In terms of metal physics, the steels under consideration differed in the value of the experimentally determined SFE. The SFE of the AISI 304L was 22.7 ± 0.8 mJ/m2 and the SFE of the 304 mod alloy was 18.7 ± 0.4 mJ/m2. The tensile specimens tested in air revealed a direct γàα’ conversion for AISI 304L and an indirect γàεàα’ conversion for 304mod. From the results it could be deduced that the indirect phase transformation is responsible for a significant increase in the content of deformation-induced α’-martensite due to a reduction of the SFE value below 20 mJ/m2 in hydrogen gas atmosphere.

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