amirhossein mashhuriazar | AmirKabir University Of Technology (original) (raw)

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University of the Basque Country, Euskal Herriko Unibertsitatea

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Papers by amirhossein mashhuriazar

Research paper thumbnail of Effect of Laser Metal Deposition Parameters on the Characteristics of Stellite 6 Deposited Layers on Precipitation-Hardened Stainless Steel

Materials

Laser metal deposition (LMD) is one of the manufacturing processes in the industries, which is us... more Laser metal deposition (LMD) is one of the manufacturing processes in the industries, which is used to enhance the properties of components besides producing and repairing important engineering components. In this study, Stellite 6 was deposited on precipitation-hardened martensitic stainless steel (17-4 PH) by using the LMD process, which employed a pulsed Nd:YAG laser. To realize a favor deposited sample, the effects of three LMD parameters (focal length, scanning speed, and frequency) were investigated, as well as microstructure studies and the results of a microhardness test. Some cracks were observed in the deposited layers with a low scanning speed, which were eliminated by an augment of the scanning speed. Furthermore, some defects were found in the deposited layers with a high scanning speed and a low frequency, which can be related to the insufficient laser energy density and a low overlapping factor. Moreover, various morphologies were observed within the microstructure of...

Research paper thumbnail of Effects of heat input on metallurgical behavior in HAZ of multi-pass and multi-layer welded IN-939 superalloy

Journal of Materials Research and Technology

Research paper thumbnail of Experimental and Numerical Investigation on the Effect of the Tempcore Process Parameters on Microstructural Evolution and Mechanical Properties of Dual-Phase Steel Reinforcing Rebars

Metals and Materials International

Research paper thumbnail of Effect of Welding Parameters on the Liquation Cracking Behavior of High-Chromium Ni-Based Superalloy

Journal of Materials Engineering and Performance

Research paper thumbnail of Effects of Pre-Weld Heat Treatment and Heat Input on Metallurgical and Mechanical Behaviour in HAZ of Multi-Pass Welded IN-939 Superalloy

Metals

Heat-affected zones (HAZs) of Inconel 939 (IN-939) superalloy are susceptible to cracking during ... more Heat-affected zones (HAZs) of Inconel 939 (IN-939) superalloy are susceptible to cracking during welding process. Preventing cracking during the repair welding of turbine components is important. In this study, the effects of heat input and pre-welding heat treatment on the microstructure, mechanical properties and crack formation in tungsten inert gas welding of IN-939 were investigated. The whole specimens were welded using Inconel 625 filler in an Ar atmosphere and characterised by metallographic examinations and hardness measurements. Results showed that the microstructures of IN-939 HAZs were highly susceptible to cracking during welding due to increasing of γ′ volume fraction. All of these cracks appeared in the HAZs and grew perpendicular to the melting zone along the grain boundaries. In this survey, the pre-welding heat treatment and heat input strongly affected the HAZ microstructure and hardness. However, the pre-welding heat treatment with 67% impact was more effective t...

Research paper thumbnail of Effect of Laser Metal Deposition Parameters on the Characteristics of Stellite 6 Deposited Layers on Precipitation-Hardened Stainless Steel

Materials

Laser metal deposition (LMD) is one of the manufacturing processes in the industries, which is us... more Laser metal deposition (LMD) is one of the manufacturing processes in the industries, which is used to enhance the properties of components besides producing and repairing important engineering components. In this study, Stellite 6 was deposited on precipitation-hardened martensitic stainless steel (17-4 PH) by using the LMD process, which employed a pulsed Nd:YAG laser. To realize a favor deposited sample, the effects of three LMD parameters (focal length, scanning speed, and frequency) were investigated, as well as microstructure studies and the results of a microhardness test. Some cracks were observed in the deposited layers with a low scanning speed, which were eliminated by an augment of the scanning speed. Furthermore, some defects were found in the deposited layers with a high scanning speed and a low frequency, which can be related to the insufficient laser energy density and a low overlapping factor. Moreover, various morphologies were observed within the microstructure of...

Research paper thumbnail of Effects of heat input on metallurgical behavior in HAZ of multi-pass and multi-layer welded IN-939 superalloy

Journal of Materials Research and Technology

Research paper thumbnail of Experimental and Numerical Investigation on the Effect of the Tempcore Process Parameters on Microstructural Evolution and Mechanical Properties of Dual-Phase Steel Reinforcing Rebars

Metals and Materials International

Research paper thumbnail of Effect of Welding Parameters on the Liquation Cracking Behavior of High-Chromium Ni-Based Superalloy

Journal of Materials Engineering and Performance

Research paper thumbnail of Effects of Pre-Weld Heat Treatment and Heat Input on Metallurgical and Mechanical Behaviour in HAZ of Multi-Pass Welded IN-939 Superalloy

Metals

Heat-affected zones (HAZs) of Inconel 939 (IN-939) superalloy are susceptible to cracking during ... more Heat-affected zones (HAZs) of Inconel 939 (IN-939) superalloy are susceptible to cracking during welding process. Preventing cracking during the repair welding of turbine components is important. In this study, the effects of heat input and pre-welding heat treatment on the microstructure, mechanical properties and crack formation in tungsten inert gas welding of IN-939 were investigated. The whole specimens were welded using Inconel 625 filler in an Ar atmosphere and characterised by metallographic examinations and hardness measurements. Results showed that the microstructures of IN-939 HAZs were highly susceptible to cracking during welding due to increasing of γ′ volume fraction. All of these cracks appeared in the HAZs and grew perpendicular to the melting zone along the grain boundaries. In this survey, the pre-welding heat treatment and heat input strongly affected the HAZ microstructure and hardness. However, the pre-welding heat treatment with 67% impact was more effective t...

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