Wyniki wyszukiwania - BazTech

1

Operation-Oriented Studies on Wear Properties of Surface-Hardened Alloy Cast Steels Used in Mining in the Conditions of the Combined Action of Dynamic Forces and an Abrasive Material

Wieczorek A. N.

Archives of Metallurgy and Materials

|

2017

|

Vol. 62, iss. 4

2381--2389

EN

This paper presents the results of wear tests of shot-peened and not shot-peened cast steels used in the mining machinery industry, in particular in the construction of chain drums for armoured face conveyors. Wear tests were carried out in the conditions corresponding to the real operating conditions of armoured face conveyors during drifting work in rocks such as sandstone. The operating factors subjected to the analyses included the presence of quartz abrasive and the impact of external dynamic forces. On the basis of the wear tests as well as the microhardness and microstructure examinations performed, it has been found that the action of an additional dynamic force has a synergistic impact on the process of abrasive wear in loose quartz abrasive. It has been further found that the value of abrasive wear of chain wheels operated in the conditions of a combined action of abrasive and a dynamic force depends on whether the area of mating of wheels with the chain was shot-peened or not before the wear tests – an increase in the abrasive wear was observed for the wheels made of cast steel subjected to shot peening in the area of mating with the chain. Lower resistance to abrasive wear of the cast steels subjected to shot peening before the wear tests could result from the formation of cracks in the surface layer caused by the action of shot.

2

Comparative Studies on the Wear of ADI Alloy Cast Irons as Well as Selected Steels and Surface-Hardened Alloy Cast Steels in the Presence of Abrasive

Wieczorek A. N.

Archives of Metallurgy and Materials

|

2017

|

Vol. 62, iss. 1

119--128

EN

The paper presents the results of wear tests obtained for 4 groups of materials: surface-hardened alloy steels and alloy cast steels for structural applications, hard-wearing surface-hardened alloy cast steels, and austempered alloy cast irons. The wear tests have been performed on a specially designed test rig that allows reproducing the real operating conditions of chain wheels, including the rolling and sliding form of contact between elements. The chain wheels subjected to tests were operated with the use of loose quartz abrasive. This study presents results of measurements of material parameters, micro-structure of a surface subject to wear, as well as the linear wear determined for the materials considered. Based on the results, the following was found: the best wear properties were obtained for surface-hardened alloy steels and wear surface; strengthening of the ADI surface took place - most probably as a result of transformation of austenite into martensite; the uniformity of the structure of the materials affects the surface wear process. The study also indicated a significant degree of graphite deformation in ADI characterized by the upper ausferritic structure and its oblique orientation in relation to the surface, which resulted in a facilitated degradation of the surface caused by the quartz abrasive.

3

Influence of Low-Alloy Cast Steel Modification on Primary Structure Refinement, Type and Shape of Non-Metallic Inclusions

Bartocha D., Suchoń J., Baron C., Szajnar J.

Archives of Metallurgy and Materials

|

2015

|

Vol. 60, iss. 1

77--83

EN

In the article there are presented methods and results of investigation which main aim were determination of influence of melting technology (gas extraction, vacuum refining, slag refining and extraction, deoxidation and degassing) and type of used modifiers on the type and shape of non-metallic inclusions and the primary structure refining. Low alloy cast steel melted in laboratory conditions, in an inductive furnace was investigated. Additions of FeNb, FeV, FeTi and FeZr modifiers were applied. The contents of oxygen and nitrogen in obtained cast steel were determined. The most advantageous impact on refining of the primary structure of has been found for the modifiers FeTi+FeZr. In cast steel with the addition of Zr the conglomerates from a different non -metallic inclusions have been observed. Zirconium probably plays role of the nucleus - creating for other inclusions present in the conglomerates. Clusters of inclusions due to their size affect the crystallization and grain growth processes reducing grain size of the primary structure.

PL

W pracy przedstawiono założenia, metodykę i wyniki badań, których celem było określenie wpływu technologii wytopu (ekstrakcji gazowej, rafinacji próżniowej, rafinacji i ekstrakcji żużlowej, odtleniania i odgazowania) i rodzajów zastosowanych modyfikatorów na postać i rodzaj wtrąceń niemetalicznych oraz rozdrobnienie struktury pierwotnej. Analizie poddano nisko-stopowe staliwo wytopione w warunkach laboratoryjnych w piecu indukcyjnym. Zastosowano dodatek modyfikatorów FeNb, FeV, FeTi i FeZr. W uzyskanym staliwie określono zawartość O i N oraz jego skład chemiczny. Stwierdzono najkorzystniejsze, ze względu na rozdrobnienie struktury pierwotnej, oddziaływanie modyfikatora FeTi+FeZr. Zaobserwowano występowanie konglomeratów różnych wtrąceń niemetalicznych w staliwach z dodatkiem Zr, który prawdopodobnie działa zarodkotwórczo na pozostałe wtrącenia wchodzące w skład konglomeratów. Skupiska wtrąceń ze względu na swoje rozmiary wpływały na krystalizację i wzrost ziaren staliwa rozdrabniając jego strukturę pierwotną.

4

Production of steel casts in two-layer moulds with alkaline binders. Part 1. Backing sand with the alkaline inorganic binder RUDAL

Holtzer M., Drożyński D, Bobrowski A., Tomczak M., Rozmiarek E., Isendorf B.

Archives of Foundry Engineering

|

2011

|

Vol. 11, iss. 2

41-46

EN

Steel casts in Z.N. POMET were produced in moulds made of the moulding sand Floster. This sand did not have good knocking out properties, required a significant binder addition (4.5-5.0 parts by weight), and the casting surface quality gave rise to clients objections. Therefore a decision of implementing two-layer moulds, in which the facing sand would consist of the moulding sand with an alkaline organic binder while the backing sand would be made of the moulding sand with an inorganic binder also of an alkaline character - was undertaken. The fraction of this last binder in the moulding sand mass would be smaller than that of the binder used up to now (water glass). The application of two moulding sands of the same chemical character (highly alkaline) should facilitate the reclamation process and improve the obtained reclaimed material quality, due to which it would be possible to increase the reclaim fraction in the moulding sand (up to now it was 50%). The results of the laboratory investigations of sands with the RUDAL binder are presented in the paper.

PL

Odlewy staliwne w Z.M. POMET wykonywane były w formach z masy Floster. Masy te posiadały niezbyt dobrą wybijalność, konieczny był znaczny dodatek spoiwa (4,5-5,0 cz. wag.), a jakość powierzchni odlewów budziła zastrzeżenia klientów. Dlatego też podjęto decyzję o wdrożeniu form dwuwarstwowych, w których masę przymodelową stanowiłaby masa ze spoiwem organicznym o charakterze alkalicznym, a masę wypełniającą masa ze spoiwem nieorganicznym również o charakterze alkalicznym, którego udział w masie byłby mniejszy niż dotychczasowego spoiwa (szkła wodnego). Zastosowanie dwóch mas o tym samym charakterze chemicznym (wysoce alkaliczne) powinno znacznie ułatwić proces regeneracji i poprawić jakość otrzymywanego regeneratu, dzięki czemu możliwy będzie większy udział regeneratu w masie (dotychczas było to 50%). W artykule przedstawiono wyniki badań laboratoryjnych masy ze spoiwem RUDAL.

5

Production of Steel Casts in Two-Layer Moulds with Alkaline Binders. Part 2: Facing sand with the alkaline organic binder REZOLIT

Holtzer M., Bobrowski A., Drożyński D., Tomczak M., Rozmiarek E., Isendorf B.

Archives of Foundry Engineering

|

2011

|

Vol. 11, iss. 2 spec.

81--86

EN

This paper constitutes the second part of the article concerning the implementation of the two-layer mould technology for steel casts in Z.M. POMET. The results of the laboratory examinations of the backing sand with the inorganic binder RUDAL were presented in the first part of the paper. Whereas in the second part the results of the laboratory testing of the facing sand with the alkaline resin REZOLIT are given. The technology of two-layer moulds was already implemented in Z.M. POMET within the target project. Examples of castings made in this technology are shown in the final part of this paper.

PL

Jest to 2 część artykułu dotyczącego wdrożenia technologii form dwuwarstwowych do wykonywania odlewów staliwnych w Z.M. POMET. W części 1 przedstawiono wyniki badań laboratoryjnych masy wypełniającej ze spoiwem nieorganicznym RUDAL. Natomiast w części 2 zamieszczono wyniki badań laboratoryjnych masy przymodelowej z żywicą alkaliczną REZOLIT. Technologia form dwuwarstwowych została już wdrożona w Z.M. POMET w ramach projektu celowego. W końcowej części artykułu zamieszczono przykłady wykonanych odlewów w tej technologii.

6

Specyfika kwalifikowania technologii spawania odlewów staliwnych wg PN-EN ISO 11970:2009

Mazur Ł.

Biuletyn Instytutu Spawalnictwa w Gliwicach

|

2009

|

R. 53, nr 5

62-65