Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: dissimilar welded joints

Sortuj według:

Ogranicz wyniki do:

Effect of filler metal composition on microstructural and mechanical characterization of dissimilar welded joint of nitronic steel and super duplex stainless steel

Maurya Anup Kumar, Pandey Chandan, Chhibber Rahul

Archives of Civil and Mechanical Engineering

2022

Vol. 22, no. 2

art. no. e90, 1--28

The present paper experimentally investigates the effect of filler metal on the mechanical behavior, solidification, and microstructure of the super duplex stainless steel (sDSS2507) and nitronic steel (N50) dissimilar welded joint. This dissimilar joint is primarily applicable in the subsea control unit for high-pressure tubing and coupler assembly. For this investigation, the gas tungsten arc welding process (GTAW) employed the super duplex filler ER2594 and carbon steel grade ER70S-2 filler. The weld's structural integrity has been assessed to compare both the fillers through multiple investigations on the joint. The microstructure characterization of the base metal and as-welded specimen was carried out using an optical microscope (OM) and scanning electron microscope (SEM). Super duplex filler ER2594 weld solidified in primary ferritic mode with precipitation of several reformed austenite in the ferrite matrix, whereas ER70S-2 filler weld had long marten site laths embedded in ferrite matrix. The microstructural study reported the presence of microsegregation and Type II boundary formation. The type-II boundary is detected close to the fusion boundary at the N50 and the sDSS 2507 side of the ER70S-2 weldment. The Vickers microhardness test, Charpy impact test, and the tensile test were performed to obtain the mechanical properties of this joint. The microhardness investigation of the weld zone of ER2594 and ER70S-2 shows the average hardness of 287.34±10 Hv0.5 and 372.36±10 Hv0.5, respectively. The peak hardness of 410 Hv0.5 was observed in the weld zone of ER70S-2. The formation of large marten site laths in the ferrite matrix in the weld zone leads to higher hardness in ER70S-2 filler compared to the precipitation of softer reformed austenite in the ER2594 fller. The average impact toughness result of ER2594 and ER70S-2 is 165±5 J and 110±8 J, respectively. The Charpy impact trials showed the ductile fracture mode by employing ER2594 filler, while ER70S-2 showed the mixed fracture mode (ductile-brittle). The weldment tensile strength of filler ER2594 and ER70S-2 is 897 MPa and 873 MPa, respectively. The tensile test results indicate the ductile fracture mode for both fillers, and the failures were detected in sDSS2507.

Microstructure and Properties of Dissimilar Welded Joints Made of Steels used in the Power Industry

Pańcikiewicz K., Ziewiec A., Kajda P., Tasak E., Zbroja P.

Biuletyn Instytutu Spawalnictwa w Gliwicach

2014

Vol. 58, No. 5

145--150

The article presents the microstructure and properties of dissimilar welded joints of pipes made of the 304HCu (X10CrNiCuNb18-9-3) and P92 (X10CrWMoVNb9-2) steels in the as welded state and after PWHT. The test-related TIG welding was carried out using two filler metals in the form of the Thermanit 304HCu and the EPRI P87 filler metal wires. The tests revealed the significant influence of heat treatment time extension on the decrease in the hardness of the martensitic steel and its HAZ as well as an on the increase in the hardness of the austenitic steel, its HAZ and of the weld made using the Thermanit 304HCu filler metal. The microscopic observations revealed the presence of a carburised zone on the fusion line between the P92 steel and the weld made using the Thermanit 304HCu filler metal wire.

W artykule przedstawiono mikrostrukturę oraz własności połączeń różnoimiennych rur ze stali 304HCu (X10CrNiCuNb18-9-3) i P92 (X10CrWMoVNb9-2) w stanie surowym po spawaniu oraz po obróbce cieplnej. Do spawania metodą TIG wykorzystano dwa materiały dodatkowe – drut Thermanit 304HCu oraz drut EPRI P87. Badania wykazały istotny wpływ wydłużenia czasu obróbki cieplnej na obniżenie twardości stali martenzytycznej i jej SWC oraz wzrost twardości stali austenitycznej, jej SWC i spoiny wykonanej spoiwem Thermanit 304HCu. Obserwacje mikroskopowe ujawniły występowanie strefy nawęglonej na linii wtopienia pomiędzy stalą P92 a spoiną utworzoną przy użyciu drutu Thermanit 304HCu.