Wyniki wyszukiwania - Biblioteka Nauki

1

Defects Appearing in the Surfacing Layers of Abrasion Resistant

100%

Bęczkowski R. , Gucwa M.

|

tom Vol. 16, iss. 4

23--28

EN

The surfacing technologies are used for constitution of protection layer against wear and is destined for obtaining coating with high hardness. Among many weldings methods currently used to obtain the hard surface layer one of the most effective way of hardfacing is using flux cored arc welding. This additional material gives more possibilities to make expected hard surface layer. Chemical composition, property and economic factors obtained in flux cored wire are much richer in comparison to these obtained with other additional materials. This is the reason why flux cored wires give possibilities of application this kind of material for improving surface in different sectors of industry. In the present paper the imperfection in the layers was used for hardfacing process in different situations to show the possible application in the surface layer. The work presents studies of imperfection of the welds, contains the picture of microstructures, macrostructures and shows the results of checking by visual and penetrant testing methods.

2

Structure and Properties of Coatings Made with Self Shielded Cored Wire

80%

Gucwa M. , Winczek J. , Bęczkowski R. , Dośpiał M.

|

tom Vol. 16, iss. 3

39--42

EN

The welding technologies are widely used for design of protection layer against wear and corrosion. Hardfacing, which is destined for obtaining coatings with high hardness, takes special place in these technologies. One of the most effective way of hardfacing is using self shielded flux cored arc welding (FCAW-S). Chemical composition obtained in flux cored wire is much more rich in comparison to this obtained in solid wire. The filling in flux cored wires can be enriched for example with the mixture of hard particles or phases with specified ratio, which is not possible for solid wires. This is the reason why flux cored wires give various possibilities of application of this kind of filler material for improving surface in mining industry, processing of minerals, energetic etc. In the present paper the high chromium and niobium flux cored wire was used for hardfacing process with similar heat input. The work presents studies of microstructures of obtained coatings and hardness and geometric properties of them. The structural studies were made with using optical microscopy and X- ray diffraction that allowed for identification of carbides and other phases obtained in the structures of deposited materials. Investigated samples exhibit differences in coating structures made with the same heat input 4,08 kJ/mm. There are differences in size, shape and distribution of primary and eutectic carbides in structure. These differences cause significant changes in hardness of investigated coatings.

3

Identification of Lack of Fusion and Incomplete Penetration in Butt Weld Joint by Ultrasonic Phased Array Method and X-Ray Method

80%

Koňár R. , Mičian M. , Boháčik M. , Gucwa M.

|

tom Vol. 64, iss. 3

1117--1124

EN

The main goal of the article is to identify artificially created defects like lack of fusion and incomplete penetration in buttweld joint using non-destructive volumetric methods. These defects are the most serious defects in welds of steel constructionsfrom the safety point of view. For identification, an ultrasonic phased array technique and a conventional X-ray using digital imaging were used. The theoretical part of the article describes the current state of the given issue and provides basic theoretical knowledge about ultrasonic and X-ray welding tests. In the experimental part, the procedure and results of testing butt weld joint are described by both non-destructive methods. The butt weld joint was made from steel S420MC. Each indication obtained by the ultrasonic and x-ray technique is supplemented by the macrostructure of the weld taken from the indication position. The results of the experimental work mentioned in the article point to the possibility and reliability of the identification of melting defects by selected nondestructive methods in terms of their character and orientation.

4

Optymalizacja struktury i właściwości staliwa gatunków Cr-Mo i Cr-Mo-V przeznaczonych do pracy w podwyższonej temperaturze

80%

Stachura S. , Kupczyk J. , Gucwa M.

|

tom Vol. 54, nr 5

402-408

PL

W pracy przedstawiono opracowane przez autorów wykresy CTP dla staliwa gatunków G17CrMo5-5 i G17OMoV5-10, pomocne przy ustalaniu zakresu szybkości chłodzenia odlewów z temperatury austenityzowania, aby uzyskać optymalną strukturę bainityczną. Wykazano, ze struktura odpuszczonego bainitu, charakteryzująca się dużymi wartościami właściwości wytrzymałościowych i bardzo dużą udarnością KV > 100 J, zapewnia uzyskiwanie udarności KV > 27 J także w staliwie o strukturze, zdegradowanej długotrwałą eksploatacją w podwyższonej temperaturze.

EN

The work presents the CTP diagrams developed by the authors for cast steel grades G17CrMo5-5 and G17CrMoV5-10, which are helpful when determining range of casting cooling rate from austenitizing temperature in order to obtain optimal bainitic structure It hes been proved that tempered bamite structure, which features high strength characteristic values and very large impact strength KV > 100 J, ensures that impact strength values KV > 27 J are obtained also in cast steel with structure degraded by prolonged operation in increased temperature.

5

The Analysis of Filler Material Effect on Properties of Excavator Crawler Track Shoe after Welding Regeneration

71%