13345

12164

كارشناسي ارشد

جوشكاري

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

۱۳۹۶

سيزده، ۸۶ص.: مصور، جدول، نمودار

مرتضي شمعانيان، عبدالمجيد اسلامي

مهران نحوي

محمود منير وافقي، عباس بهرامي

1396/12/15

كتابنامه

مواد

مهندسي مواد

ID12164

AbstractIn this study Mn Ni Cr alloy was sprayed on AISI 321 stainless steel substrates using athermal flame spray technique For this purpose the flame spraying method was used to createthe coating of the aforementioned alloy as an interface layer in the brazing process Regardingthe importance of the absence of oxide phases in the coating argon and nitrogen was used as acarrier gas for the brazing The microstructure of coated samples was studied using scanningelectron microscopy SEM It was observed that when used instead of air from argon andnitrogen as carrier gas the amount of spreading splats was reduced and the porosity andprosity in the coating increased Surface coatings were investigated by X ray diffraction and itwas observed that the use of protective gases reduced and eliminated some of the oxides Inthis study due to the high number of samples the samples were first coated with air under thebrazing process to obtain optimal parameters of temperature and time The samples coatedwith argon and nitrogen gas at optimal temperature and time were subjected to brazing Also a foil with a similar composition of braze alloy was used to perform the brazing process Theprocess was performed by choosing a temperature of 1150 C as a constant temperature andchanging the time of brazing process from 5 to 45 minutes to determine the optimum time The results obtained from microstructural reviews and tensile strength tests indicate anoptimum time of 45 minutes then at time of 45 minutes and the Temperature at 1110 C and1130 C samples were brazed Tensile strength test results indicate temperature of 1150 C foroptimum temperature Therefore the samples coated with neutral gases as well as the desiredfoil were brazed at optimal temperature and time Among of the samples coatted with thehighest strength is 116 MPa and the minimum strength is 45 MPa This is while the strength ofthe foil brazed sample is 405 MPa The main factor in the strength of the brazing process is themanganese element which can be completely dissolved in iron and form a strongmetallurgical bond Investigation of microstructure images and distribution of elements indicating that the formation of solid solution and a brittle phase is not formed On the otherhand the main reason is the strength difference between the samples brazed by coating andfoil the surface discontinuities on the substrate that was created during the sand blastingprocess Keywords AISI 321 Stainless Steel Braze alloy Flame Spray Brazing Manganese

مرتضي شمعانيان، عبدالمجيد اسلامي

مهران نحوي

محمود منير وافقي، عباس بهرامي