Wyniki wyszukiwania - BazTech

1

The life time of super 304H austenitic steel power boiler components under the unstable operation conditions

Dobrzański J., Zieliński A., Purzyńska H.

Archives of Materials Science and Engineering

|

2015

|

Vol. 76, nr 2

115--121

EN

Purpose: The purpose of the work was to analyse the components of Super 304H (X10CrNiCuNb18-9-3) steel steam pipelines of power units after long-term service beyond the design work time. Design/methodology/approach: The material for investigations included the 4th stage steam superheater coils, in the form of ø 42.4 x 8.8 mm pipes, made from Super 304H (X10CrNiCuNb18-9-3) steel, intended for operation under creep conditions at the design temperature 620°C and design pressure 28.5 MPa. Findings: The effect of cyclic creep, and therefore shut-downs and repeated start-ups after long-term service under creep conditions beyond the design work time was determined. Research limitations/implications: Practical implications: The presented method can be used for evaluation and qualification of structural changes in power station boiler components operating under creep conditions. Originality/value: The obtained results of investigations will be the elements of material characteristics developed by the Institute for Ferrous Metallurgy for steels made from them working under creep conditions.

2

Austenitic steels or boiler elements in USC power plantsAustenitic steels or boiler elements in USC power plants

Zieliński A.

Journal of Achievements in Materials and Manufacturing Engineering

|

2013

|

Vol. 57, nr 2

68--75

EN

Purpose: Characteristics of functional properties of austenitic- based steels used for construction of boilers with supercritical and ultra-supercritical steam parameters. Design/methodology/approach: For selected austenitic steels in as-received state and after long-term annealing microstructural investigations were carried out with scanning and transmission electron microscope. Findings: Selected characteristics of structure and functional properties of materials to be used for critical elements in the pressure selection of power boilers were summarized in a single paper. Practical implications: The steel characteristics presented in this paper are used for assessment of structural changes and changes in strength properties of material o elements after long-term service under creep conditions. Originality/value: The presented results of the mechanical properties, structure and in the precipitation processes are applied to evaluation the condition of the elements in further industrial service.

3

Pękanie na gorąco stali nierdzewnych austenitycznych z dodatkiem miedzi

Ziewiec A.

Hutnik, Wiadomości Hutnicze

|

2012

|

Vol. 79, nr 7

476--482

PL

W artykule przedstawiono wyniki badań skłonności do pęknięć gorących stali nierdzewnej austenitycznej 304HCu. Stal została poddana próbie pękania gorącego. Ustalono, że stal 304HCu wykazuje bardzo dużą skłonność do pęknięć zarówno krystalizacyjnych, jak i segregacyjnych. Przeprowadzono badania SEM z obszaru powstałych pęknięć po próbie. Zaobserwowano, że w miejscach pęknięć występuje dwukrotnie większa zawartość miedzi w stosunku do wartości średniej w badanej stali.

EN

This work presents the studies of susceptibility to hot cracking in 304HCu austenitic stainless steel. The steel was subjected to hot cracking test. It was found that the 304HCu steel has a very high susceptibility both to crystallization crack and segregation cracks. The SEM observations of the cracks after the cracking test were performed. It was observed that concentration of copper in the regions of cracks is twice as much than the average concentration of copper in the steel.