Search Results

You are looking at 1 - 7 of 7 items for

  • Author: M. Korzeniowski x
Clear All Modify Search
Open access

M. Korzeniowski and B. Białobrzeska

Abstract

The article presents the possibilities of using acoustic microscopy to evaluate defects in resistance spot welding joints. For this purpose, the welded joints were made from two grades of aluminium plates EN AW5754 H24 and EN AW6005 T606, which were then subjected to non-destructive testing using acoustic microscopy and conventional destructive testing using traditional light microscopy techniques. Additionally, the study examined the influence of the typical contaminants found in industrial conditions on the quality of the joint.

Open access

A. Ignasiak, M. Korzeniowski and A. Ambroziak

The paper presents results of metallographic investigations of spot welds made of high-strength steel HSLA340 and dual-phase DP600 steel. Low-carbon martensite microstructure was found in the weld nugget of HSLA steel. The DP600 steel shows martensite and bainite microstructure. For both steels, no carbides of microadditives were found because they dissolved in liquid nugget and could not precipitate again because of rapid heat abstraction. Moreover, no transcrystallisation was found in both steels, which proves good mixing of the materials within the weld.

Open access

M. Korzeniowski, T. Piwowarczyk, P. Kustroń and A. Czubak

ABSTRACT

The paper deals with the issues of welding modern car-body steels (including dual phase (DP), high strength low alloy (HSLA) and deep-drawing (DC) grades) using low-energy methods. In view of small thickness of elements to be joined, welding them with conventional arc methods has becoming more and more rare and has been replaced with methods which, while ensuring required strength properties of joints, deliver substantially less heat to the weld, thus limiting its effect on the structure being welded. Examinations (visual inspections, strength tests, hardness measurements) allowed an objective evaluation of selected low-energy methods with respect to MAG welding with CO2 shielding.

Open access

T. Piwowarczyk1, M. Korzeniowski, P. Kustroń and M. Gąbka

ABSTRACT

The paper presents the potential of robotized welding applied for thin steel sheets using variable parameters of arc (different welding programs: Standard, Pulse, Twin Pulse, and Speed Pulse). Trial welded joints were made for sheets 0.8 to 1.25 mm thick and relevant welding parameters were selected for them during the first stage of examinations. The properties of welded joints were determined with non-destructive and destructive testing. In turn, visual inspection allowed to evaluate the shape and dimensional conformities of joints and to detect superficial imperfections. In order to improve detection accuracy, penetration testing was used for confirmation purposes. Tensile strength testing was also made to determine mechanical properties of the weld and the heat-affected zone. Metallographic examinations were used for sheets of all thickness values and for all welding programs to verify that the structure of joints was correct. All examinations and tests made on trial joints enabled to find how pulsing arc welding affects quality and strength properties of welds as compared with standard method.

Open access

A. W. Orłowicz, M. Mróz, M. Tupaj, A. Trytek, B. Kupiec, M. Korzeniowski, D. Pająk, K. Sondej and L. Kozak

Abstract

The paper presents results of an analysis of material density distribution in stampings press-moulded in metal dies from raw refractory materials based on alumina-magnesia-carbon aggregate. The stampings, fabricated on LAEIS HPF 1250 pressing machine, are blanks from which refractory precast shapes are manufactured by means of drying and firing. Samples for material density evaluation were cut out from test stampings with the use of diamond-reinforced disc. Density of the material was determined in thirteen layers of stampings denoted with letters A through M.

Open access

A.W. Orłowicz, M. Mróz, M. Tupaj, A. Trytek, B. Kupiec, M. Korzeniowski, K. Sondej and L. Kozak

Abstract

NC11 steel, in view of the specificity of its manufacturing process, is characterised with band-like orientation of carbides. Depending on the direction of cutting the material for the inserts out of commercially available steel products, carbide bands can be oriented in parallel or perpendicularly to the direction in which aggregate grains move in the process of pressing stampings. It has been found that in case of scratches made in direction perpendicular to carbide bands, depth of the scratches is less than this observed when scratches are made in direction coinciding with prevailing orientation of carbide precipitates.

Open access

A.W. Orłowicz, M. Mróz, Z. Cisek, M. Tupaj, A. Trytek, B. Kupiec, M. Korzeniowski, K. Sondej and L. Kozak

Abstract

The paper presents results of assessment of the unit pressure force within the refractory material volume in the course press-moulding of stampings for refractory precast shapes. The force was evaluated with the use of physical simulation of deformation undergone by lead balls placed in the raw refractory mass subjected to pressing in a metal die. To determine the value of unit pressure force applied to the aggregate grains in the course of stamping press-moulding, physical model of deformation of a sphere induced by the uniaxial stress state was used.