Marcin Knapinski posted an update 6 years, 3 months ago
LABORATORY OF PHYSICAL MODELLING OF PLASTIC WORKING PROCESSES
In September 2003, one of Poland’s most cutting edge laboratories for mechanical properties research and physical simulation of metallurgical processes was launched. The laboratory is equipped with a system for physical modelling of metallurgical processes GLEEBLE 3500, produced by an American company Dynamic Systems Inc. It’s a device that enables conducting physical simulations for processes such as: continuous casting of steel, rolling, drawing, forging, extrusion, and welding. The system also allows to conduct research on plastic properties of materials for plastic working processes, structural research on plastic deformation mechanisms, and to determine material characteristics. Here are the basic technical parameters of the device: sample heating rate: 10000 °C/s, max. pressure force: 100kN, max. speed of the mobile jaw: 1000 mm/s. All trials can be conducted in lower pressure conditions or protective atmosphere. The device can be utilised in research conducted by employees dealing with plastic working processes, metallurgy workers dealing with extraction and recirculation of metals, as well as materials engineering teams. The biggest advantage of this workstation is its versatility and the possibility of adjusting to different metallurgy research.
The basic scope of usage of the simulator:
• developing new technologies of rolling in continuous systems
• normalizing rolling technologies
• thermomechanical rolling technologies
• continuous casting technologies
• analysing thermomechanical properties of new materials
• determining the influence of plastic working on the internal structure and strength of materials
The device is especially useful in case of scientific researches requiring determination of mechanical properties of a material and describing it in an analytical way. The generated models are then used for computer simulations of actual processes. Moreover, the workstation enables modelling of mechanical properties of finished products from new materials or based on new thermomechanical working technologies.
The GLEEBLE system has many unique features that are not available in any other material testing machine. All the advantages together create a system with unparalleled possibilities regarding simulation processes and material study. Here are a few of its key features:
– Very fast cooling
– Freezing of microstructure
The equipment for fast cooling is placed directly inside the machine. For that reason, it is not necessary to move the heating furnace or removing a sample for cooling down. Moreover, thermocouples remain connected to the sample during cooling. Thanks to that, the operator knows the exact temperature on the surface of the sample during cooling.
Comparing the heating instrumentation of the tool for hot heading trials with the GLEEBLE system, the most important advantage of the GLEEBLE simulator is its high productivity. In case of a hot drawing trial, the system can conduct 4 tests per hour. In case of typical devices equipped with heaters, only one trial per 3÷4 hours is possible. Therefore, GLEEBLE’s productivity might be 12÷16 times better compared to devices with heaters. Comparing heading tests, GLEEBLE allows for 3÷10 trials in the same time the machines with heaters need to conduct one trial.
– Isothermal planes
One of the most important technical issues in case of thermal and thermomechanical measuring machines is temperature distribution in an analysed sample. It has to be checked in two conditions: static and dynamic. In static conditions, it is quite easy to obtain consistent temperature with the use of a heater or induction heating, but usually in real conditions there are no static phenomena. The temperature in hot feedstock, tank, or ingot is always changeable. The way it’s changing is a critical parameter for proper modelling of the process. During induction heating and cooling with atomised liquid, the heat is added up and taken away by the surface of a sample. The measurement takes place on the surface as well, therefore the temperature inside the sample might be behind or ahead of the actual value provided by the programme even by several hundred degrees, depending on the heating or cooling speed. The temperature might finally reach balance, but it might happen a few minutes after the surface reached the required temperature. With the use of GLEEBLE’s heating system, the core and the surface of a sample have the same temperature during hating up and cooling down (unless cooling with atomised liquid on the surface was applied). Therefore, if a sample is heated up to 1000°C in 3 seconds, the core also reaches 1000°C in 3 seconds. During induction heating the system can notify about reaching 1000°C a few minutes before the core actually reaches the temperature, depending on sample measurements. During cooling the GLEEBLE simulator receives heat through the ends of a sample, therefore the surface and the core have the same temperature. It generates transverse ISOTHERMAL planes in a sample during fast heating and cooling. The importance of the issue can be seen on the example of critical application – Continuous Cooling Transformation (CCT). In case of using bars with the diameter of 6, 10 and 12 mm in a device with induction heating (or cooling with atomised liquid) in the CCT programme for cooling at the same speed for each of the three diameters, we will obtain different transformation temperatures for each diameter, which proves that there was an evident mistake in the measuring method or the experiment. Conducting the same trial with GLEEBLE, we will obtain identical temperatures, as they should be, regardless the diameter. It is caused by the existence of isothermal planes.
– Dynamic temperature control
The GLEEBLE system provides the possibility of dynamic heating and cooling at high speeds. For HAZ (HEAT-AFFECTED-ZONE) simulations (welding processes) high speeds are of the greatest importance. For precise control over the system, it should have the possibility of adding and taking away the heat at much greater speed than required for simulation. With the possibility of heating at the speed exceeding 10000°C/s, GLEEBLE can easily and precisely control the speed of heating and cooling. Considering the entry power limits, heating and cooling with the use of induction systems are limited as well.
– Possibility of very fast heating
The GLEEBLE simulator enables heating of samples at the speed of over 10000°C/s with precise computer control and maintaining stable temperature balance. Such heating speed is obtained for carbon steel bars with the diameter of 6 mm and the length of 15 mm, with 3-phase power source of 360V and drain rate of 200A.
– Possibility of very fast cooling
GLEEBLE’s cooling speeds are controlled by conductivity. The controlled cooling rate depends on the size, shape and temperature of a sample. At the temperature of 1000°C cooling speed of 140°C/s can be obtained for a carbon steel bar with the diameter of 6 mm. The heating system enables smooth transition from the state of thermal balance to maximum cooling speed for a specific sample size and type (acc. to specification). For very fast cooling processes, an external cooling system can be applied, which enables obtaining the speed of over 10000°C/s on the surface of a sample (in case of flat samples that are 1 mm thick).
– Selection of different temperature control methods
The source of feedback signal for temperature control can be thermocouples or optional infrared pyrometer. Thermocouples are automatically linearized. GLEEBLE is equipped with one Cr-Al thermocouple channel (Type K) and one Platyna-Platynorod channel (Type S, 10% or Type R, 13%) as standard accessory. Other linearizations are also possible. The optional system of pyrometer control enables measuring the temperature without contact on the surface of a sample in cases when application of thermocouple is inconvenient or impractical.
– Areas of consistent temperature
GLEEBLE also generates an area of consistent temperature inside a sample through application of hot jaws made of corrosion-proof steel in the grips. Such area of stable temperature can be evened out on the length depending on trial requirements. For example, in a round carbon steel bar with the diameter of 10 mm and the length of about 50 mm, the central part of sample that is 7 mm long has the temperature of about ±0.5% of the average temperature value for this area.
– Horizontal placement of a strained element
GLEEBLE is based on a horizontal design. A sample is placed horizontally. It has a lot of advantages. A heated sample doesn’t cause the stack effect, as it often happens in case of vertical machines. The upper end of a sample has higher temperature then, due to the fact that the sample is heating itself. GLEEBLE eliminated this problem by horizontal sample placement. Additionally, the trial is not interrupted by the weight of the upper jaw.
– Significant variability of sample sizes and shapes
GLEEBLE is characterised by flexible jaw system, which enables utilisation of different grips for many sample sizes. There are over 20 different sample configurations available for GLEEBLE. After combining them with different sample sizes, it provides over 50 different shape and size combinations that can be analysed in this machine. It gives the freedom to choose the right sample for a particular simulation or a mechanical test, which makes the machine more flexible regarding utilisation.
GLEEBLE 3800 has many unique features that are not available in any other material testing machine. All the advantages create a system with unequalled possibilities within the scope of process simulations and material studies. The architecture of GLEEBLE 3800 is a module system. Such system enables flexibility in configuration of the device, depending on the researcher’s needs.
Key elements of the GLEEBLE 3800 system:
• Stationary computer
• Industrial computer
o System for cooling and filtration of water
o Negative pressure station
o Pneumatic system
o PocketJaw Module
o Hydrawedge Module
o MaxStrain Module
o Torsion Module
• Transverse strain measurement sensor
• Longitudinal strain measurement sensor
• Rapid cooling system – outside
• Rapid cooling system – inside
• Thermocouple welder
• QuikSim programme – Gleeble System
• Standard software package for processing research results- Origin
The ultimate tool for optimizing hot rolling and forging processes.
For researchers who wish to optimize multiple-hit, high-speed deformations — including multi-stand rolling mills and multi-hit forging processes — the Hydrawedge offers excellent physical simulation capabilities.
Available as a stand-alone machine or as an option for a Gleeble system, the Hydrawedge is the only commercially available machine that offers the capability to perform high-speed deformation simulations with complete independent control of both strain and strain rate.
Through its patented technology, the Hydrawedge delivers test results without strain overshoot or strain rate deceleration, either one of which can reduce the validity of the simulation.
The Hydrawedge control software allows the system to be programmed like a rolling mill schedule. Enter soaking times and temperatures, rolling temperature, interpass time, controlled cooling time, and strain rate and amount of strain for each stand; the software then calculates and programs how to run that schedule on the Hydrawedge.
The Hydrawedge offers unsurpassed capability to simulate high-speed deformation. To learn more about the hydrawedge’s unique capability set and how it can add value to your research or production line please contact us today.
MAXStrain® Multi-Axis Hot Deformation System
A research tool for making ultrafine-grain and nano materials
The MAXStrain multi-axis hot deformation system is a unique research tool that can subject materials to virtually unlimited strain under precise control of strain, strain rate, and temperature.
The system restrains specimens lengthwise while allowing unlimited deformation in the other two dimensions. As a result, very high strain levels can be introduced into specimens to produce a sample of ultrafine-grain or nanoscale material that is large enough for subsequent properties testing.
The MAXStrain system can be used on steels, aluminum alloys, titanium, and other metals.
Because the MAXStrain provides unparalleled, accurate control of all parameters,it offers a high degree of reproducibility. Researchers quickly and precisely create materials in the laboratory under well controlled mechanical and thermal conditions.
Hot Torsion Mobile Conversion Unit
The Hot Torsion Mobile Conversion Unit (MCU) adds world-class hot torsion testing capability to the Gleeble 3500 and 3800 Systems.
Capable of applying torque up to 100 Nm (50 Nm standard configuration), Hot Torsion Systems from Dynamic Systems are the first commercially available torsion systems to incorporate direct resistance heating.
► Rapid, uniform direct resistance heating of samples
► Heating of test specimens at any time during torsion
► Rapid in-situ quenching of the test specimen at any point in the test (DR heating only)
► Use air, water or mist for quench media
► Apply controlled tension axially during torsion
► Torsion tests can be conducted with full axial restraint or no axial restraint
► High-speed hydraulic torque motor for rapid strain rate changes
► Variable torsion coupler for higher acceleration speeds
► Free coupler minimizes strain error during specimen loading
► Optional specimen furnace available
Tests may be performed in vacuum (10-2 torr), inert gas or air (Atmosphere tank is included, vacuum pumps are optional)
► Temperature is controlled by a thermocouple attached to the fixed end of the specimen.
► Specimen size: Gage length diameter: 6 mm to 10 mm diameter
Gage length: 6mm to 50 mm
► Longitudinal load cell with overload protection provides measurement of axial load on specimen
► Torque cell with overload protection provides accurate torque measurements during test.
► Axial load control provides combined stress states such as tension – shear and compression – shear.
► A torsion free coupler minimizes acceleration times.
► Optional quench systems can be used as in-situ quenching to accelerate cooling or to freeze microstructures of the specimen.
► The Gleeble Series 3 Digital Control and Data Acquisition System is used to control the test and acquire test results. All software is Windows based. Variables include:
• Temperature program
• Actual specimen temperature (multiple channels)
• Axial force on specimen