The paper presents the results of preliminary studies on the properties of products made by vitrification of waste containing fly ashes from sewage sludge incineration. The performed tests of hazardous substances leached from the ashes, as well as the results of other laboratory tests confirmed the efficacy of vitrification. It has been found that the resulting products (sinters) could be used as a substitute aggregate for road foundations.

High-alloy corrosion-resistant ferritic-austenitic steels and cast steels are a group of high potential construction materials. This is

evidenced by the development of new alloys both low alloys grades such as the ASTM 2101 series or high alloy like super or hyper duplex

series 2507 or 2707 [1-5]. The potential of these materials is also presented by the increasing frequency of sintered components made both

from duplex steel powders as well as mixtures of austenitic and ferritic steels [6, 7]. This article is a continuation of the problems presented

in earlier works [5, 8, 9] and its inspiration were technological observed problems related to the production of duplex cast steel.

The analyzed AISI A3 type cast steel is widely used in both wet exhaust gas desulphurisation systems in coal fired power plants as well as

in aggressive working environments. Technological problems such as hot cracking presented in works [5, 8], with are effects of the rich

chemical composition and phenomena occurring during crystallization, must be known to the technologists.

The presented in this work phenomena which occur during the crystallization and cooling of ferritic-austenitic cast steel were investigated

using numerical methods with use of the ThermoCalc and FactSage® software, as well with use of experimental thermal-derivative

analysis.

The paper presents the results of research on the microstructure of GX2CrNiMoCuN25-6-3-3 and GX2CrNiMoCuN25-6-3 cast steels with

a varying carbon content. The cause for undertaking the research were technological problems with hot cracking in bulk castings of duplex

cast steel with a carbon content of approx. 0.06% and with 23% Cr, 8.5% Ni, 3% Mo and 2.4% Cu. The research has shown

a significant effect of increased carbon content on the ferrite and austenite microstructure morphology, while exceeding the carbon content

of 0.06% results in a change of the shape of primary grains from equiaxial to columnar.

The paper presents results of studies on the effect of the nodular cast iron metal matrix composition on the abrasive and adhesive wear resistance. Nodular cast iron with different metal matrix obtained in the rough state and ADI were tested. To research of abrasive and adhesive wear the pearlitic and bainitic cast iron with carbides and without this component were chosen. The influence of the carbides amount for cast iron wear resistance was examined. It was found, that the highest abrasive and adhesive wear resistance under conditions of dry friction has a nodular cast iron with carbides with upper and lower bainite. Carbides in bainitic and pearlitic cast iron significantly increase the wear resistance in these conditions. In terms of fluid friction the largest wear resistance had cast iron group with the highest hardness.

In the high-alloy, ferritic - austenitic (duplex) stainless steels high tendency to cracking, mainly hot-is induced by micro segregation

processes and change of crystallization mechanism in its final stage. The article is a continuation of the problems presented in earlier

papers [1 - 4]. In the range of high temperature cracking appear one mechanism a decohesion - intergranular however, depending on the

chemical composition of the steel, various structural factors decide of the occurrence of hot cracking. The low-carbon and low-alloy cast

steel casting hot cracking cause are type II sulphide, in high carbon tool cast steel secondary cementite mesh and / or ledeburite segregated

at the grain solidified grains boundaries, in the case of Hadfield steel phosphorus - carbide eutectic, which carrier is iron-manganese and

low solubility of phosphorus in high manganese matrix. In duplex cast steel the additional factor increasing the risk of cracking it is very

"rich" chemical composition and related with it processes of precipitation of many secondary phases.

The paper presents the use of rapid prototyping technology of three dimensional printing (3DP) to make a prototype shell casting mold. In

the first step, for identification purposes, a mold was prepared to enable different alloys to be cast. All molds being cast were designed in a

universal CAD environment and printed with the zp151 composite material (Calcium sulfate hemihydrate) with a zb63 binder (2-

pyrrolidone). It is designated to be used to prepare colourful models presenting prototypes or casting models and molds. The usefulness of

3DP technology for use with copper alloys, aluminum and zinc was analyzed. The strength of the mold during casting was assumed as a

characteristic comparative feature in the material resistance to high temperature, the quality of the resulting casting and its surface

roughness. Casting tests were carried out in vacuum – pressure casting. The casting programs applied, significantly increased the quality of

castings and enabled precise mold submergence. Significant improvement was noted in the quality compared to the same castings obtained

by gravity casting.

In a reality of global competition, companies have to minimize production costs and increase productivity in order to boost com-petitiveness. Facility layout design is one of the most important and frequently used efficiency improvement methods for reducing operational costs in a significant manner. Facility layout design deals with optimum location of facilities (workstation, machine, etc.) on the shop floor and optimum material flow between these objects. In this article, the objectives and procedure of layout design along with the calculation method for layout optimization are all introduced. The study is practice-oriented because the described case study shows how the layout of an assembly plant can be modified to form an ideal re-layout. The research is novel and innovative because the facility layout design and 4 lean methods (takt-time design, line balance, cellular design and one-piece flow) are all combined in order to improve efficiency more significantly, reduce costs and improve more key performance indicators. From the case study it can be concluded that the layout redesign and lean methods resulted in significant reduction of the following seven indicators: amount of total workflow, material handling cost, total travel distance of goods, space used for assembly, number of workers, labor cost of workers and the number of Kanban stops.