Modern Machinery (MM) Science Journal, December 2010

DEVELOPMENT OF NEW TYPES OF TOOL STEELS DESIGNED FOR FORGING DIES

P. Fila, M. Balcar, L. Martinek, P. Suchmann, J. Krejcík, L. Jelen, E. Psik
Keywords: resistance to wear. | hardness and abrasion resistance | die forging | tool steel

Tool steels used for forging dies are mostly made from medium and high alloyed steels. In terms of their use at forging these steel grades are divided to grades for hammer dies and steel grades for forging press dies. In case of grades for hammer dies high toughness is required above all and alloying conception depends on it (mostly based on nickel with chromium, molybdenum and possibly vanadium). (…)

EVALUATION OF DYNAMIC FORCES ESTABLISHED DURING THE TAYLOR ANVIL TEST

M. Slais, M. Forejt, M. Knebl
Keywords: strain gauges | impact loading | high strain rate | Taylor Anvil Test

This paper deals with innovation possibilities in the measurement of dynamic forces that act on the specimen during the Taylor anvil test. The goal of this work is to decrease the influence of unwanted noises in the pulse record. The Quartz Force Link piezoelectric sensor by Kistler was used to compare the waveform of shock loading with signals recorded by foil resistance strain gauges by Hottinger (…)

MECHANICS OF SQUARE TUBES BENDING AND CROSS SECTION DISTORSION

K. Podany, R. Samek, K. Matousek
Keywords: bending forces | section distorsion | weld position | square cross section | material characteristics | tube bending

The paper deals with characteristics of plasticity and strength of tubes materials. Tested where samples with and without the seam weld, annealed and without annealing. Ideal position of the welded wall was studied with respect to neutral axis shift. This being closely connected with the mode of bending when super imposed forces are added. Analysis of the bending forces mechanics and bending stress (…)

PROCESS FORMABILITY OF STEELS USED IN AUTOMOTIVE INDUSTRY

E. Spisak, J. Hudak, M. Tomas
Keywords: limit drawing ratio | AHSS steel | process formability | deep drawing

Contribution deals with process formability evaluation of TRIP and HSLA steels, that were compared to typical deep drawing quality steel DC06. Process formability evaluation was performed by cupping test. Limit drawing ratio was used as a process formability criterion and drawing forces were measured during cupping test. There was used experimental-mathematic method for limit drawing ratio identifi (…)

MINIATURIZATION IN THIXOFORMING

B. Masek, D. Aisman, P. Hronek, H. Jirkova, S. Jenicek
Keywords: tool steel | metastable austenite | rapid cooling | Semi-Solid forming | thixoforming

Innovative technological processes can help us to obtain unconventional structures with specific mechanical properties, even from conventional materials. Forming metal alloys in the semi-solid state is one of many ways. With thixoforming the tool steel X210Cr12 was treated with rapid solidification from the liquid phase. The microstructure after processing in the semi-solid state is 96% globular au (…)