Showing 3 results for 304l Stainless Steel
Morteza Abbasi, Hamidreza Najafi, Alireza Khodabandeh,
Volume 4, Issue 1 (8-2018)
Abstract
Dissimilar welding of AISI 304L austenitic stainless steel to AISI 409 ferritic stainless steel with GMAW process usingtwo Ar-O2 and Ar-CO2 shielding gas mixtures was studied. ER316LSi and ER309LMo filler metals were chosen by considering 5 and 15% delta ferrite according to the Schaeffler equations and diagram. Based on the observations, both filler metals accompanied by Ar-2%O2 shielding gas resulted in acceptable weldments. Yield strength and UTS of tensile samples were 288 and 424 MPa, respectively. All tensile samples fractured in the ferritic base metal. Microhardness test results demonstrated that the maximum hardness of 190-200 HV was obtained from ER316LSi weld metal. The minimum hardness of 145 HV was found in the HAZ of 409 side mainly due to the grain coarsening. Microstructural examinations revealed needle-like precipitates formed perpendicular to each other in the HAZ of 409 stainless steel. It seemed that the pre-existing TiC precipitates evolved into the needle shape precipitates as a result of rapid heating and cooling rates during the welding process.
S. Ghaderi, F. Karimzadeh, A. Ashrafi,
Volume 5, Issue 2 (1-2020)
Abstract
In the present study, the effect of time and base metal microstructure on the Transient Liquid Phase (TLP) bonding of 304L stainless steel was studied. TLP was performed at 1050 0C for 5 and 60 minutes on the coarse grain austenitic and martensitic microstructure using BNi-2 interlayer. To prepare martensitic microstructure, as-received 304L was rolled at -15 0C up to 80% rolling reduction. TEM analysis was proved that the microstructure of 80% rolled samples consisted of two different morphologies of martensite namely as lath-type and dislocation cell type martensite. It was observed that the structure of bonded zone after 5 min has consisted of isothermally solidified zone (ISZ) containing γ solid solution and athermally solidified zone (ASZ) containing complex boride phases. Meanwhile, after 60 min of heating, the structure of bonded zone completely solidifies isothermally. The obtained results also showed that the martensitic microstructure considerably effect on the width of diffusion affected zone (DAZ) which was related to the reversion of martensite to ultrafine grain austenite during heating.
Dr Behzad Binesh, Dr Sima Mirzaei, Mr Amin Taghi-Ahari,
Volume 7, Issue 2 (1-2022)
Abstract
Transient liquid phase (TLP) bonding of AISI 304L stainless steel was carried out using BNi-2 amorphous interlayer. The microstructure of the joint area was studied by using optical and scanning electron microscopes and energy dispersive spectroscopy. The effect of bonding temperature (1030-1110 °C) was studied on the microstructure and corrosion behavior of the TLP bonded samples. Electrochemical corrosion resistance of the bonded samples was evaluated in 3.5% NaCl solution at room temperature. The mechanism of the microstructure formation and the solidification sequence at the joint area were discussed. Ni- and Cr-rich borides, Ni-Si-B compound and fine Ni3Si particles were identified in the γ-Ni matrix at the joint centerline. The microstructural investigations revealed that the solidification sequence of these phases is: L→ γ + L → γ + Ni boride + Cr boride + L → γ + Ni boride + Cr boride + Ni-Si-B Compound. The highest corrosion resistance was observed in the sample bonded at 1070 °C for 30 min, which is comparable to that of the as-received AISI 304L stainless steel. It was attributed to the bond region microstructure with a negligible amount of eutectic constituents formed in the athermally solidified zone.
