The analysis of solidification process of ferritic-austenitic cast steel

Abstract One of the most common defects leading to the rejection of faulty castings made of duplex cast steel is hot cracking. Hot crackingdifferently from cold cracking which occur on cooling, when the material exhibits already distinct elastic properties -proceeds in the semi-solid state, particularly when the temperature of solidifying casting is close to the equilibrium solidus point. There exist a range of temperatures in the vicinity of the solidus point within which the solidifying metal shows very small deformation ability and small strength. Therefore even little stresses occurring at the solidification stage and caused by density difference between ferrite and austenite, or restricted shrinkage, or various temperature gradients, can be the reason of hot cracking. Copper addition, as it is used in cast steel grades implemented in Polish power industry applications, decreases the temperature of the end of solidification, thus affecting beneficially the surface reproduction quality, but on the other hand it can promote, along with several other elements contained in duplex cast steel, the peritectic transformation during the last stage of solidification. The presence of peritectic solidification, i.e. strictly speaking the structural stresses accompanying that process, is the well-known and significant reason of the increased steel defectiveness in the continuous steel casting (CSC) technology if the steel with carbon content promoting the peritectic transformation is processed. The authors have presented the examination results of the solidification phenomenon for two duplex cast steel grades -one without copper addition, and the other with addition of about 3.0% Cu

Кирило-методиевските традиции в църковнославянските ръкописи в Полиша/ Cyril and Methodius Traditions in Church Slavonic Manuscripts in Poland

Among over one thousand of Church Slavonic manuscripts which are preserved in Poland, codices from the 15th-17th century are dominant. The cult of Sts. Cyril and Methodius is attested in several manuscripts

Echa IV krucjaty w dawnej literaturze ruskiej

La IV. crociata (1204) e la caduta di Costantinopoli sotto i Turchi (1453) sono due fatti storici strettamente legati nella storiografia anticho-russa. La Mosca, lanciando l'dea di essere la terza Roma interpretava le due cadute come la punizione divina e un segno che il centro dell'ortodossia naturalmente passa verso la Russia

Analiza procesu walcowania blach bimetalowych po połączeniu metodą zgrzewania wybuchowego

This work presents the effect of plastic deformation and heat treatment on the properties of joint area of AL99,8 + M1E bimetallic plate. The joining zones were analyzed after rolling in three variants: directly after joining, after joining and annealing at 300°C, and after joining and annealing at 400°C.Praca przedstawia wpływ przeróbki plastycznej oraz obróbki ciepła na własności złącza blach bimetalowych Al99,8+M1E. Analizie zostanie poddany obszar złącza próbek po walcowanych według trzech wariantów: tj. bezpośrednio po spojeniu, po spojeniu i wyżarzaniu w 300°C oraz po spojeniu i wyżarzaniu w 400°C

Rekopisy cerkiewnoslowianskie w Polsce. Katalog

This book provides an inventory of more than one thousand Cyrillic scrolls in Polish museums and libraries. These manuscripts are strictly related to the spiritual culture of Eastern Christianity. In great part they refer to the lands of the Polish-Lithuanian Commonwealth, since they were written or circulated there. The catalogue informs about the repair and content of the scrolls and points out their Slavic specificity and their strict ties with the Balkans. The book shows the richness of the Church-Slavonic tradition and provides a basis for further investigations on Church-Slavonic literature and on the cultural relations among the various ethnic and cultural components within the Polish-Lithuanian Commonwealth, as well as on the potential of the Ruthenian component, on the Orthodox and Uniate traditions, especially in a situation of contact with the Roman-Catholic tradition. The work stimulates an evaluation of the cultural past of Central and Eastern Europe

Analysis of Bimetallic Plate Rolling after Explosive Welding/ Analiza Procesu Walcowania Blach Bimetalowych Po Połączeniu Metoda Zgrzewania Wybuchowego

This work presents the effect of plastic deformation and heat treatment on the properties of joint area of AL99,8 + M1E bimetallic plate. The joining zones were analyzed after rolling in three variants: directly after joining, after joining and annealing at 300°C, and after joining and annealing at 400°C.Praca przedstawia wpływ przeróbki plastycznej oraz obróbki ciepła na własności złącza blach bimetalowych Al99,8+M1E. Analizie zostanie poddany obszar złącza próbek po walcowanych według trzech wariantów: tj. bezpośrednio po spojeniu, po spojeniu i wyżarzaniu w 300°C oraz po spojeniu i wyżarzaniu w 400°C

The Effect of the Asymmetrical Rolling Process on Structural Changes in Hot-Rolled Bimetal Sheets

The paper presents research results on the selection of parameters for the asymmetric rolling process of bimetallic plates 10CrMo9-10+X2CrNiMo17-12-2. They consisted in determining the optimum parameters of the process, which would be ensured to obtain straight bands. Such deformation method introduces in the band the deformations resulting from shear stress, which affect changes in the microstructure. But their effect on the structure is more complicated than in the case of homogeneous materials. It has been shown that the introduction of asymmetric conditions into the rolling process results in greater grain refinement in the so-called hard layer. There was no negative effect on the structural changes in the soft layer observed