Kondapalli Siva Prasad

A Review on Welding of AISI 304L Austenitic Stainless Steel

Abstract 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 switch components. The low carbon content reduces susceptibility to carbide precipitation during welding. In the present paper a thorough review on welding of AISI 304L austenitic Stainless Steel by various welding processes was made. From the review it is understood that AISI 304L austenitic Stainless Steel is the best material where there is a problem of intergranular corrosion. Also it is one of the best materials frequently used in manufacturing non heat treatable components.

Review on Application of Response Surface Method based Design of Experiments to Welding Processes

Design of Experiment is one of the extensively used method for experimental study of many manufacturing processes in engineering. In welding, Design of Experiments are widely used to develop a mathematical relationship between the welding input parameters and the output variables of the weld joint in order to determine the welding input parameters that lead to the desired weld quality. In the present study, a review is made on Response Surface Method based Design of Experiments that have been employed for various welding processes by other researchers. This study predominantly focuses on the usage of Response Surface Method in Welding.

Optimizing Pulsed Current Micro Plasma Arc Welding Parameters to Maximize Ultimate Tensile Strength of SS304L Sheets Using Hooke and Jeeves Algorithm

SS 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 SS304L 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 and its adequacy is checked by ANOVA technique. By using the developed mathematical model, ultimate tensile strength of the weld joints can be predicted with 99% confidence level. Contour plots are drawn to study the interaction effect of welding parameters on ultimate tensile strength of SS304L weld joints. The developed mathematical model has been optimized using Hooke and Jeeves Method to maximize the ultimate tensile strength.

Study of Weld Quality Characteristics of Inconel 625 Sheets at Different Modes of Current in Micro Plasma Arc Welding Process

Inconel 625 is a Nickel alloy which was used in fabrication of high temperature resistance and corrosion resistance components, such as metal bellows used in expansion joints in aircraft, aerospace and petroleum industry. The paper focuses on studying the effect of continuous current and pulsed current in welding Inconel 625 sheets using Micro Plasma Arc Welding (MPAW) process. Welding was carried out on 0.25 mm thick Inconel 625 sheets using continuous current mode and pulsed current mode separately keeping all other welding parameters constant. Weld quality characteristics like bead profile, micro structure, hardness and tensile properties are investigated and it is found that the usage of pulsed current leads to better weld quality characteristics when compared to continuous current mode

Study of Factors Effecting Surface Roughness and Tool Tip Temperature in Step Turning Using Factorial Technique

The paper focuses on the effect of various process parameters like spindle speed, feed, depth of cut, nose radius and machining condition on the Tool tip temperature and surface roughness in step turning process is investigated by using Factorial Technique. Five factorsTwo levels are used and total 32 experiments are performed. The coefficients are calculated by using regression analysis and the model is constructed. The adequacy of the developed model is checked using Analysis of Variance (ANOVA) technique. By using the mathematical model the main and interaction effect of various process parameters on tool tip temperature and surface roughness are studied.

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

Effect of Welding Current Mode on Weld Quality Characteristics of Pulsed Current Micro Plasma Arc Welded AISI 304L Sheets

Austenitic stainless steels have gathered wide acceptance in the fabrication of components, which require high temperature resistance and corrosion resistance, such as metal bellows used in expansion joints in aircraft, aerospace and petroleum industry. In case of single pass welding of thinner sections of this alloy, pulsed current micro plasma arc welding was found beneficial due to its advantages over the conventional continuous current process. The paper focuses on studying the effect of continuous current and pulsed current in welding AISI 304 L sheets using Micro Plasma Arc Welding (MPAW) process. Welding was carried out on 0.25 mm thick AISI 304 L sheets using continuous current mode and pulsed current mode separately keeping all other welding parameters constant. Weld quality characteristics like micro structure, hardness and tensile properties are investigated and it is found that the usage of pulsed current leads to better weld quality characteristics when compared to continuous current mode.

Unconstrained Optimization for Maximizing Ultimate Tensile Strength of Pulsed Current Micro Plasma Arc Welded Inconel 625 Sheets

Nickel alloys had gathered wide acceptance in the fabrication of components which require high temperature resistance and corrosion resistance. The paper focuses on developing mathematical model to predict ultimate tensile strength of pulsed current micro plasma arc welded Inconel 625 nickel alloy. 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 and its adequacy is checked by ANOVA technique. By using the developed mathematical model, ultimate tensile strength of the weld joints can be predicted with 99% confidence level. Contour plots are drawn to study the interaction effect of welding parameters on ultimate tensile strength of Inconel 625 weld joints. The developed mathematical model has been optimized using Hooke and Jeeves Method to maximize the ultimate tensile strength.

Optimizing fusion zone grain size and hardness of pulsed current micro plasma arc welded Inconel625 sheets using Hooke and Jeeves Algorithm

Purpose – The purpose of this paper is to optimize the fusion zone grain size and hardness using Hooke and Jeeves Algorithm.Design/methodology/approach – Experiments are conducted as per four factors, five levels response surface method based central composite design matrix. Empirical relations for predicting grain size and harness are developed. The effect of welding variables on grain size and hardness are studies. Grain size and hardness are optimised using Hooke and Jeeves Algorithm.Findings – The developed empirical relations can be effectively used to predict grain size and hardness values of micro plasma arc welded Inconel 625 sheets. The values of grain size and hardness obtained by Hooke and Jeeves Algorithm matches with experimental values with great accuracy.Research limitations/implications – The developed mathematical models are valid for 0.25 mm thick Inconel 625 sheets only.Practical implications – In the present paper only four important factors namely peak current, back current, pulse rat...

Study on Effect of Welding Speed on Micro Structure and Mechanical Properties of Pulsed Current Micro Plasma Arc Welded AISI 304L Sheets

Abstract Micro Plasma Arc Welding (MPAW) is one of the important arc welding process commonly used in sheet metal industry for manufacturing metal bellows, metal diaphragms etc. In the present paper welding of AISI 304L austenitic chromium-nickel stainless steel using pulsed current micro plasma arc welding was discussed. The paper mainly focuses on studying the weld quality characteristics like weld pool geometry parameters, microstructure, grain size, hardness and tensile properties of Pulsed Current Micro Plasma Arc Welded AISI 304L austenitic stainless steels at different welding speeds. Results show that a welding speed of 260 mm /minute yield better weld quality characteristics.