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The ferritic rolling strategy allows for the production of two different hot strip grades, a "soft" and a "hard" hot strip. The "soft" hot strip is rolled in the upper ferrite region and a sufficiently high coiling temperature ensures direct recrystallisation in the coil. The "hard" hot strip is rolled at relatively lower temperatures in the ferrite temperature region and exhibits a strained microstructure with a desirable rolling texture. Furthermore, these ferritic rolled hot strips can be used as initial strip for subsequent cold rolling. The current investigation focuses on the development of the recrystallisation texture of cold rolled and annealed ferritic rolled hot strip for different cold reductions. For this purpose "soft" and "hard" hot strips were produced on a laboratory hot rolling mill. These strips were cold rolled with a total reduction of 40 to 80% to a final thickness of 0.5mm. Subsequently the strips were subjected to simulated continuous annealing, using a salt bath furnace. The macro texture of both types of specimens was measured and correlated to the mechanical properties, including the Lankford values. A very different development of the recrystallisation texture and hence mechanical properties has been observed. However, both grades yielded improved deep-drawing properties.

Ultrafine ferrite grains in a plain C–Mn steel (0.3 mass% C) were produced by large-strain warm compression and subsequent annealing treatment in a temperature range between 773 K and 1003 K. The samples were investigated by means of high-resolution electron back-scatter diffraction. The resulting microstructures showed very fine ferrite grains and homogeneously distributed cementite particles. The majority of the grain boundaries (55–70 %) were classified as high-angle ones (≥ 15° misorientation). When considering only these high-angle grain boundaries, the average grain size changed from 0.9 mm at a deformation temperature of 773 K to 2.2 mm at a deformation temperature of 1003 K. For the same range the average subgrain sizes increased from 0.6 mm to 1.5 mm. The basic result of this study is that the grain size characterization of polycrystalline microstructures with ultrafine grains requires the use of the high-resolution electron back-scatter diffraction method in conjunction with a careful a...

An ultrafine microstructure was produced in plain C-Mn steels with different carbon contents (0.15 - 0.3 mass% C) by heavy warm deformation. The rolling was simulated by the plane strain compression test with a simulated post rolling coiling. The final microstructure consists of an ultrafine grained ferrite matrix with the average grain size of 1.1 - 1.4 μm and spheroidized cementite particles of two different size groups. The fraction of high-angle grain boundaries maintained in the range of 60% to 65%. With the increase of C content from 0.15 mass% to 0.3 mass% the strength increases by about 100 MPa, while the total elongation of 23% hardly changes. The (specific) upper shelf energy decreases from 320 J/cm 2 to 236 J/cm 2 but a rather low ductile-to-brittle transition temperature (DBTT) of about 206 K does not rise with increasing C content. The ultrafine steel with higher C content (0.3 mass%) exhibits a superior strength-toughness combination.

By using a thin slab casting simulator combined with the hot deformation simulator WUMSI, laboratory tests were performed to investigate the microstructure processes and mechanical properties in the process of thin slab direct rolling (TSDR). The paper shows the possibilities to improve the initial as-cast state of microstructure prior to hot rolling (microvoids, dendritic structure, austenite grain size, state of precipitation). The main part of the study is dedicated to the role of microalloying and sulphur for the austenite grain control and for the precipitation hardening in the final structure. On examples of selected low carbon steel grades the effect of the variation of the process parameters of hot rolling and cooling on the microstructure and mechanical properties is presented.

Subsize specimens in Charpy impact tests has are a valuable substitute to predict the ductile-to-brittle transition temperature (DBTT) and the upper shelf energy (USE) anticipated for full size specimens where volume limitations exist. The subsize specimens have been applied to testing of several steels and the data has been compared to those of standard full size specimens. The common normalization on the basis of fracture area does not produce any correspondence between the two different sized specimens therby showing an apparent decrease in both USE and DBTT by using subsize specimens.

In the so-called ferritic rolling the finishing is shifted down into the temperature region of ferrite, which enables a production of thinner hot strips (compared to the conventional hot rolling in austenite) with a changed texture development. The present study is focused on the effect of the process parameters of such initial warm rolled hot strips on the texture formation and hence on the deep-drawing quality of the final cold strips. A special attention is given to the transmission of the hot strip texture to the cold strip. The investigation was carried out on commercial IF- and ELC-steels by a laboratory simulation with the hot deformation simulator Wumsi (rolling simulated by the plane strain compression test). It was possible to optimize cold rolling and subsequent annealing by means of the measurements of the texture development during the ferritic (warm) deformation as well as the parameters of the processing route of such special production of cold strips by means of the calculation of r-values. If compared with the conventional processing route, a considerable improvement of deep-drawability with a diminished earing is achievable especially with the IF-steel.

In order to produce ultra-thin hot strips by ferritic rolling, that exhibit a good deep-drawability, finishing temperatures must be reduced, so that an additional recrystallization annealing of hot strips after coiling becomes necessary. In the present work laboratory investigations were carried out on a commercial IF and ELC steel by using the hot deformation simulator Wumsi. By means of texture measurement and the calculation of r-values the process parameters of the ferritic rolling and of a subsequent annealing were optimized. Additionally to a conventional annealing of cold coils a new energy saving processing route with direct charging of warm coils was tested by the laboratory simulation. Particularly good deep-drawabilty were achieved by this technology.

Phosphorus as a tramp element deteriorates the toughness and enhances the brittle fracture in high strength steels. Even very low bulk concentrations can cause severe enrichment on the prior austenite grain boundaries. This seriously restricts the applicability of highly demanded vehicle components. Three approaches were chosen to reduce the detrimental effect of phosphorus in quenched and tempered high strength CrV-steels for high power leaf springs: Change in the chemistry (addition of boron for repelling phosphorus from the grain boundaries), application of thermomechanical treatment (TMT) instead of conventional heat treatment (CHT) (producing lattice defects as intragranular traps for phosphorus atoms) and optimizing the tempering process (balancing grain boundary segregation and lattice restoration). Whereas no effect of boron was determined, TMT reduces the sensitivity to phosphorus and leads to better ductility, especially for the highest strength R m > 2000 MPa. The best strength - ductility combination was found for the range of tempering temperatures ∂ temp between 280 and 330 °C even for phosphorus contaminated steels. Outside of this range of ∂ temp , there is a significant deterioration of ductility for P ≥ 0.02 %. Independent of P-content, there is a dramatic decrease in 0.2 % proof strength for ∂ temp decreasing below 280 °C due to residual internal stresses.

In a conventional production of deep-drawable sheets of steel, a hot rolling in austenite and a cold rolling at room temperature together with a subsequent recrystallization annealing are applied with a cold strip as a final product. As a cost saving replacement for this, a thin-gauge hot strip with a required deep-drawability can be employed. A conventionally (in austenite) hot rolled strip is hardly applicable for this because of its unsatisfactory texture as well as because of the technical difficulties to produce hot strips with sufficiently small thicknesses. As a promising realization of cost saving thin-gauge deep-drawable hot strips of steel, a warm rolling can be applied with reduced finish rolling temperatures. In this practice the finish rolling is shifted down into the temperature region of ferrite. In the present work extensive laboratory tests on IF- and ELC-steel were carried out by using the hot deformation simulator Wumsi. By the measurements of the texture development as well as by the computing of r-values, the process parameters of ferritic rolling and a subsequent direct recrystallization in the coil of these steels could be optimized.

The determination of the fatigue properties of steel is of concern to design components that endure cyclical load. Such measurements involve a large experimental effort. For this reason the (more simple) tensile test on notched specimens was applied as an alternative method to predict the fatigue strength from easier attainable (static) data. A good correlation was obtained.

In a conventional production of deep-drawable steel sheets, a hot rolling in austenite and a cold rolling at room temperature together with a subsequent recrystallization annealing are applied to achieve a desired texture in the final cold strip. As a cost saving replacement for this, a thin-gauge hot strip with a required deep-drawability can be employed by applying the ferritic rolling with the finishing shifted down into the temperatures below Ar 1 . To optimize the process parameters, laboratory tests on an IF steel were carried out by using the hot deformation simulator WUMSI. By the measurements of the texture development as well as by the computing of r-values, the texture formation in a hot strip after ferritic rolling could be optimized achieving a deep-drawability in hot strips comparable to that of a cold strip.

In the dieless drawing technology the drawing dies are replaced by a heating device, generally by an induction coil. Bars of different cross-sections, round or even rectangular, with varying dimensions along the length can be produced. By using a cooling box in connection with the heating device this deformation process may also be employed for a thermomechanical treatment of steels. The special cooling strategy with low cooling rates at high temperatures (during ferrite formation) and higher cooling rates at lower temperatures favours the formation of multiphase microstructures (ferrite - bainite/martensite) with a low yield strength but a strong work hardening effect. The experiments were carried out on rods with a diameter of 16 mm of a plain low carbon steel (0.1%C, 0.7%Mn). The specimens were locally heated up to the maximum temperature ∂ max that initiates the dieless drawing process, and subsequently cooled with different coolants. The change in yield strength and tensile strength and the corresponding change in the ratio of both could be achieved by variation of ∂ max and the cooling conditions. The multiphase microstructure with desired mechanical properties was produced at a strain of about more than 0.45 within the region of ∂ max 900 - 1000 °C and a finale cooling rate of about 20 K/s.

In the last years, the automotive industry has been demanding a continuous reduction of weight in order to compensate for the introduction of new constructive components according to higher requirements on passenger safety and driving comfort, as well as to accomplish with new strict environmental regulations. The adoption of new materials with improved mechanical properties and/or lower density, together with modern cost effective processing technologies have contributed greatly to reach the above objectives [1]. Particularly microalloyed steels, which may provide a higher strength with small alloying additions and low heat treatment expenses, have evolved into an important category of engineering materials suitable for the manufacturing of hull, frame and motor components. As an example, the classical quench and tempering (QT) of alloyed steels followed by straightening operations and stress relieving cycles has been progressively substituted by the continuous cooling (CC) of more economical microalloyed steels from the forging temperature. An accurate control of the cooling rate adjusts the properties of the ferritic-pearlitic microstructure obtained. This technology results in lower processing costs and eliminates product rejectances due to quench-cracking. However there are limitations in the mechanical properties achievable by this processing route if compared with the QT-operation [2], and hardly any cooling rate may be encountered which would lead to a balance of strength and ductility comparable to that after QT. In this context a new post forging treatment (two-step cooling, TSC) has been presented elsewhere [3] as a promising alternative to the CC of medium carbon microalloyed steels. This paper is focused on the particular contributions of different microalloying additions with optimized deformation schedules to improve the mechanical properties achievable through this new technology.

Microalloyed forging steels with medium carbon content were hot deformed followed by direct cooling in two steps (,,slow-fast-cooling) and additional annealing at relatively low temperatures. The development of the complex ferrite-bainite/martensite microstructure during the cooling and annealing treatment was systematically investigated and correlated with mechanical properties. By applying this processing properties comparable with those of quenched and tempered Cr-alloyed steels can be obtained.

For more than twenty years the classical quench and tempering of medium carbon Cr-alloyed steels has been substituted in the production of drop-forged parts for the automotive industry by a direct continuous cooling of less expensive V-microalloyed steels with lower carbon content. However, this simplified treatment has serious limitations concerning the yield strength and ductility if compared with the properties after quench and tempering. On a group of such V-bearing steels additionally microalloyed with Ti and Nb and with different N contents, an alternative two-step-cooling (TSC) strategy after forging, combined with an additional annealing (AN), has been applied. This new post forging treatment results in a significant improvement of the final mechanical properties. The paper is focused on the particular contributions of a different microalloying in the optimized deformation schedules to improve mechanical properties after TSC + AN. The aim of this additional microalloying is to achieve a more homogeneous distribution of ferrite in the final multi-phase microstructure due to a proper austenite conditioning as well as to make a full use of the strengthening potential of vanadium in these forging steel grades.

Direct charging of thin slabs of low carbon steel (0.05%C) was investigated by using laboratory tests on a thin-slab-casting simulator linked with the hot deformation simulator (Wumsi). Starting with a different initial thickness of simulated thin slabs (45 down to 25 mm) the total strain eΣ was varied. Hot deformation schedules (with and without roughing) with different finishing temperatures TF lead to some differences in the hot strip microstructure. Nevertheless, after cold rolling and batch annealing, a rather uniform pancake-structure and a pronounced {111}-texture were achieved in the cold strip without any significant relation to the processing routs. The measurement of final mechanical properties proved that a good deep drawability of cold strip can be achieved with direct charging of thin slabs, well comparable to that after a conventional cold charging of thick slabs.

[EN]: In drop forging of parts for the transport industry the classical quench and tempering (QT) of alloyed steels is nowadays substituted by direct continuous cooling (CC) of microalloyed steels with elimination of quench cracking and expensive straightening and stress relieving cycles. Nevertheless, there are some limitations on strength and toughness achievable by this technique. On two commercial medium carbon (0.3%C) steels microalloyed with vanadium or vanadium and titanium, modified forging parameters and a new two‐step cooling (TSC) strategy combined with an additional annealing were applied. Some increase in manufacturing costs, when compared to CC, can be justified by a significant increase in strength and ductility. The improvements attainable through such a modified treatment give evidence of the large potential of multi‐phase ferrite‐containing microstructures as a substitute of a tempered martensite., The work has been financially supported by the funds of the Bundesministerium für Wirtschaftofthe FRO, through the Arbeitsgemeinschaft industrieller Forschungsvereini-gungen (AiF) and by the Comision Interministerial de Ciencia y Tecnologia (CICYT) of Spain which are gratefully acknowledged.

A possibility to characterize the different stages of the process of ductile fracture from a more microscopic point of view are micromechanical damage models. On a steel 27MnSiVS6 microalloyed additionally with titanium, which belongs to the group of the microalloyed precipitation hardening ferritic-pearlitic steels, different states of microstructure (ferrite-pearlite, tempered martensite, bainite) were produced using thermomechanical treatment. On such specimens fracture mechanics tests were done with side-grooved 1/2 CT-specimens and the results were compared with those obtained by a numerical simulation based on the modified Gurson model. A good agreement between calculated and measured JR-curves also for a thermomechanical treated steel with separations was found. The critical distance l c has a great influence on the results of this numerical model. A qualitative relation between this parameter and the average inclusion spacing, which depends on the microstructure, was found.

In the concept of direct charging linking continuous casting with rolling of thin slabs, some differences in the design of process parameters are necessary. By example of a commercial low carbon NbTi-microalloyed steel, laboratory tests have been carried out by using a thin-slab continuous casting simulator on-line with the hot deformation simulator Wumsi. The influence of the temperature of intermediate holding (between casting and rolling), total strain e Σ , finishing temperature and cooling rate after finishing on the microstructure and mechanical properties was investigated on rolling schedules with or without roughing prior to finishing. Conventional cold charging (with reheating of thicker slabs) was simulated as a comparison to this. Whereas the static properties (tensile test) were less influenced by e Σ and by the design of rolling schedule (with or without roughing), the properties measured by the low temperature impact test (at -30 °C) were more sensitive. By the optimizing process parameters of direct charging (finishing at temperatures of lower austenite, employing accelerated cooling after rolling) mechanical properties superior to those of cold charging (despite of largely reduced e Σ ) are attainable.

Considering coarse initial austenite grain and the reduced thickness of directly charged thin slabs, a modified thermomechanical treatment was carried out on an unalloyed engineering steel with 0.66% C. For the laboratory simulation to determine the microstructural and mechanical properties a continuous casting simulator linked with the hot deformation simulator (Wumsi) were used. The aim of these tests was to study the process of the strain induced spheroidization of lamellar pearlite in order to improve the cold deformability of the steel, taking account of the particular conditions of direct charging. By the variation of hot rolling deformation schedules, the influence of austenite grain size, pearlite interlamellar spacing as well as strain and strain temperature were investigated. The spheroidization process was mostly influenced by the strain applied just after finished pearlite transformation. Improving both strength and ductility by increasing fraction of spheroidized pearlite was supported by a smaller pearlite interlamellar spacing before deformation. A coarse austenite grain hardly affects the spheroidization process and brings about no impairment of mechanical properties, which makes this processing particularly attractive for direct charging of thin slabs. Moreover, a finely spheroidized pearlite exerts structural similarities to a tempered martensite, concerning distribution, shape and size of the cementite, accordingly leading to comparable mechanical properties. This justifies such modified hot rolling to be accepted as a potential substitution for the conventional post-rolling quench and tempering of high carbon steel products.

On four grades of medium carbon V-bearing steels with additional Ti and Nb microalloying hot deformation tests were conducted as a simulation of hot forging. The aim of the study was to suggest general guidelines for the design of deformation patterns and cooling conditions of austenite. Both the resulting flow stresses and the strengthening/softening behaviour were taken into consideration. The maximum flow stresses appear to be insensitive both to the variation of microalloying and to the design of the deformation schedule over the range tested. Nevertheless, large differences can be achieved regarding austenite strengthening, especially its residual value at the begin of the γ-α-transformation which is decisive for the subsequent transformation process. A substantial effect of the final deformation temperature and the type of microalloying was ascertained.

In the high-production-drop-forging of parts for automobile and truck engines the classical quench and tempering (QT) of low-alloyed steels is nowadays - in a lot of plants in Europe - substituted by direct continuous cooling (CC) of microalloyed steels without the necessity of additional heat treatment and expensive straightening as well as stress relieving cycles. Nevertheless, there are some limitations on strength and toughness achievable by this technique. On two commercial medium-carbon (0.3%C) steels microalloyed with vanadium or vanadium and titanium, modified deformation parameters were applied. The mechanical properties, determined by the tensile test, can be improved by decreasing the deformation temperature. Nevertheless, the values of yield strength (resp. 0.2%-proof stress) as well as reduction of area remain inferior to those after QT of the same steels.

The effect of austenite deformation on the transformation behaviour was investigated on a CrV-spring steel with the major attention put on the martensitic transformation. In the first part, a small review is given on the relation between the state of austenite after hot deformation and its influence on the formation of martensite. In the laboratory tests, the second part of the paper, a conventional heat treatment (CHT) was compared with two types of austenite conditioning by thermomechanical treatment (TMT) : TMTR - with deformation above the recrystallization temperature vR leading to a fully recrystallized austenite and TMT N - with deformation below vR with a not recrystallized but possibly polygonized austenite. For the laboratory tests, the hot deformation simulator Wumsi was employed. After quenching in oil, the martensite after TMT consisted of associations of many fine fragments with a smaller number of large acicular martensitic units than observed after CHT. In both TMT-variants small ferritic areas (< 1 pm) could be revealed. Different behaviour of martensite during tempering at low temperatures was observed after CHT and TMT. It can be explained by reduced inherent stresses generated during martensitic transformation after TMT, presumably as a result of a better ability of deformed austenite to withstand the accommodation strain during martensitic transformation. This may have considerable consequences for the toughness properties of tempered martensite.

On a classical CrV-bearing spring steel 50CrV4 (1.8159) the effects of thermomechanical treatment (TMT) and additional microalloying with titanium and niobium on the processes in austenite were investigated. The aim of this study was to achieve an austenite state, that promises -after subsequent quench and tempering- mechanical properties of spring steels superior to those after conventional treatment. For laboratory tests the hot deformation simulator Wumsi was employed. It was found that after reheating to usual austenitization temperatures the austenite microstructure of steel 50CrV4 is widely uninfluenced by the initial as-delivered microstructure. Despite the finer austenite grain size occurring after austenitization, additional microalloying with Ti and Nb raises the recrystallization temperature considerably. The finding that the incubation time of austenite recrystallization can be prolonged up to several minutes by microalloying is decisive for the practical applicability of TMT. In this way the substructured state of polygonized austenite beneficial for martensite formation can be preserved over the time needed for additional production steps between hot rolling and hardening of leaf springs. Moreover, the deformation of a not recrystallizing austenite may favourably influence the distribution of undesirable tramp elements in spring steels.

With a near-net-shape continuous-casting simulator and the hot deformation simulator Wumsi, laboratory simulation tests have been performed to determine the final microstructure and the mechanical properties of a Ti-microalloyed low carbon steel for cold forming, produced in the process of direct charging of thin slabs. For two initial specimen thicknesses (45 and 25 mm) restricted values of total strain φΣ were available to improve the coarse as-cast microstructure. In a series of deformation schedules φΣ was divided systematically into two components: an austenite grain-refining strain φγ-GF (above the recrystallization-stop-temperature T RS ) and an austenite strengthening strain φγ-S (below T RS )

The effect of thermomechanical treatment on the γ – α-transformation in steel has been reviewed. It has been shown that the thermo-mechanically conditioned austenite significantly influences the kinetics of transformation due to the differences in the formation of product phases. An enhanced nucleation during the diffusion controlled transformation, as a result of austenite grain refinement and/or austenite strengthening, leads to a substantial refinement of the microstructure (ferrite grains, pearlite nodules). The deformation substructure of austenite may strongly affect the shear mechanism of the diffusionless transformation, which leads to finely fragmented martensite crystals. Such differences in the transformation characteristics result in different formation temperatures of transformation products and so to the changes in CCT diagrams.

As a substantial subject of the work reviewing the effect of thermomechanical treatment (TMT) on the γ/α-transformation of steel, this paper gives a survey of the metallurgical processes in the austenite as a consequence of hot deformation. These processes determine the properties of the austenite structure from which the transformation takes place. The dynamic and static recrystallization which refine the coarse grain formed during reheating are treated. For the case that at most minimal recrystallization occurs, the deformation structures arising from hot deformation are described under the aspect of their roll as nucleation sites for the γ/α-transformation

For the modelling of microstructure development during hot deformation operations as well as for the prediction of deformation loads stress- strain data are required. For this purpose various laboratory deformation techniques are employed. On two steel grades (medium carbon Cr-Mo steel and austenitic Cr-Ni steel) axisymmetric and plane strain compression tests as well as torsion tests were applied with the aim of comparing equivalent stress-strain curves determined by such different deformation tests. The results showed that for the calculations of deformation loads during multi-deformation industrial operations with rather small individual deformation steps, the choice of laboratory deformation test is not a critical point. Nevertheless, conflicting results are expected by an exact interpretation of stress-strain curves concerning microstructural development by using different testing methods

By varying the cooling rate in the region of the γ-α-transformation different parameters of pearlite microstructure, such as interlamellar spacing and pearlite colony size, were adjusted in a pearlitic steel with 0.79% C. Refinement of the microstructure improved the mechanical properties and the fracture mechanical properties, expressed by the J R -curve. Partial spheroidization of pearlite was achieved by deformation just after the pearlite formation (at the deformation temperature of 600 °C). Investigations on ferritic-pearlitic steels with 0.19, 0.35 and 0.45% C, thermomechanically treated in such a way, showed a significant influence of the change in pearlite morphology on the fracture properties, especially with a pearlite fraction larger than about 80%

The following conclusions summarize the results. 1. A good deep-drawability of steel assumes a favorable final texture (after a complete recrystallization) with a large fraction of {l_brace}111{r_brace} oriented grains. 2. The beneficial texture development, similar as in the case of a conventional cold strip, can be achieved already in a hot strip by finishing in a temperature region of ferrite (so-called ferritic rolling). 3. Reducing finishing temperature of ferritic rolling more favorable initial rolling texture can be generated. 4. A minimum coiling temperature (670 C for the IF-steel tested) must be met if producing deep-drawable ''soft'' hot strips directly after coiling. 5. By a further lowering of finishing and coiling temperature (to achieve thinner hot strips) ''hard'' (not recrystallized) hot strips must additionally be annealed after coiling to guarantee a complete recrystallization. Lower coiling temperatures are more beneficial for these products. (orig.)

The microstructure and texture development of a medium-carbon steel (0.36% C) during heavy warm deformation (HWD) was studied using scanning electron microscopy and electron back scattering diffraction. The spheroidization of pearlite is accelerated due to the HWD, which leads to the formation of completely spheroidized cementite already after the deformation and coiling at 873 K (600 C). The homogeneity of the cementite distribution depends on the cooling rate and the coiling temperature. The cooling rate of about 10 K/s (ferrite–pearlite prior to HWD) and deformation/coiling at 943–973 K (670–700 C) lead to a homogeneous cementite distribution with a cementite particle size of less than 1 lm. The ferrite softening can be attributed to continuous recrystallization. Even up to fairly high deformation/coiling temperatures of 983 K (710 C) the texture consists of typical deformation components. During the continuous recrystallization the amount of high angle grain boundaries can increase up to 70% with a ferrite grain size of 1–3 lm. An increase of the cooling rate up to 20 K/s (ferrite–pearlite–bainite prior to HWD) deteriorates the homogeneity of the cementite distribution and the softening of ferrite in the final microstructure.

Wahrend des Versuchsablaufs werden kontinuierlich die Probentemperatur, die Stauchkraft und der Werkzeugweg digital erfast und weiter ausgewertet. Die Ermittlung von Flieskurven ermoglicht Aussagen uber die Umformkrafte und das Entfestigungsverhalten des Werkstoffs. Die differenzierten Abkuhlkurven der gestauchten Probe liefern Informationen uber den Umwandlungsablauf im Gefuge. Die Grose der Flachstauchprobe erlaubt eine umfassende Werkstoffprufung nach der Simulation und damit eine Optimierung thermomechanischer Behandlungsverfahren. Evaluation of Computer-Controlled Hot Plane Strain Compression Tests for Investigation of Material Behaviour During the test the data of specimen temperature, deformation load and ram displacement are collected and stored. The flow curves evaluated predict actual mill loads and can be used to measure softening processes. The differentiation of the cooling curve of the deformed specimen provides information about transformation kinetics. A rather large specimen enables a comprehensive material testing of the simulated processing with the aim of the optimization of thermomechanical treatment.