7. Gleeble 3180-GTC¶
Fig. 7.1 Gleeble 3180-GTC
The Gleeble 3180-GTC provides a physical simulation system for researchers who require the quality and accuracy of a Gleeble system at an affordable price. The Gleeble 3180-GTC is ideal for weld HAZ simulations, hot tensile tests, thermal cycling, heat treatment studies, uniaxial compression and low-force tests.
The Gleeble 3180 system retains the premiere performance and reliability synonymous with Gleeble systems but in a smaller and more economical platform. The Gleeble 3180 was designed as a replacement for the famous Gleeble 1500 that dominated the physical simulation market for decades.
At the heart of the Gleeble 3180 are the features that have made all Gleeble systems world-renowned. The closed-loop direct resistance heating system continues to provide superior thermal control compared to a furnace heating method.
Material Testing Capabilities of the Gleeble 3180-GTC
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| Part Number | Description | Sold As |
|---|---|---|
| 3180 | Gleeble 3180-GTC | System |
7.1. Hydro-Mechanical¶
Every Gleeble system derives its power from a servo-controlled hydraulic system. The capabilities of the hydro-mechanical system will vary based on Gleeble options.
| Characteristic | Specification |
|---|---|
| Test Frame | Horizontal type |
| Mechanical system | Closed-loop hydraulic servo control |
| Data Acquisition Channels | User selectable, up to 16 channels simultaneously, 18-bit ADC |
| Data Sampling Rate | User selectable, up to 50 kHz. |
| Maximum Static Force in Compression | 8,165 kgf (18,000 lbs) (80 kN) |
| Maximum Static Force in Tension | 8,165 kgf (18,000 lbs) (80 kN) |
| Maximum Force Continuously Reversing (Fatigue Rating) | ±5,000 kgf (±11,023 lbs) (±49 kN) |
| Maximum Stroke Rate (no load) | 1,000 mm/s (39.36 in/s) in tension or compression |
| Minimum Stroke Rate | 0.01 mm/s (3.936996-4 in/s) in tension or compression |
| Maximum Stroke Distance | 100 mm (3.93 in) |
| Maximum Number of Compression Hits | No Specific Limit |
Note
The total number of compression hits possible is dependent upon many test characteristics. These include the number of deformations, the initial position of the hydraulic stroke, and time between deformations.
Note
Accuracy is measured at a temperature of 23°C (73°F). Maximum stroke rates are at a hydraulic pressure of 203 bar (2,950 psi) ±3 % and an oil temperature of 30°C (86°F).
Maximum Dynamic Force
The maximum dynamic force for a Gleeble 3180-GTC is based on the following graph. For a given stroke speed the hydraulic system will provide a corresponding force. All performance figures for the system are based on operating within the recommended operating region below the force vs. stroke curve. The specifications are not valid for tests conducted outside this operating range.
Hydraulic Servo Response
The graphs below shows the time and distance required for the piston to reach the programmed rate.
Fig. 7.2 Distance to achieve programmed rate.
Fig. 7.3 Time to achieve programmed rate.
Load Cell
| Characteristic | Specification |
|---|---|
| Non-linearity | ±0.1 % of full scale |
| Hysteresis | ±0.08 % of full scale |
| Non-Repeatability (Maximum) | ±0.03 % of full scale |
| Overload Rating | 150 % of full scale |
| Deflection - Full Scale | 0.076 mm (0.003 in) |
| Force Measurement Accuracy | ±1.0 % of full scale |
| Force Measurement Resolution | ±1 kgf (2.2 lbf) |
Note
Accuracy is measured at a temperature of 23°C (73°F). Maximum stroke rates are at a hydraulic pressure of 203 bar (2,950 psi) ±3 % and an oil temperature of 30°C (86°F).
Stroke Transducer
| Characteristic | Specification |
|---|---|
| Type | LVDT |
| Linear Range | ±50 mm (±2.0 in) |
| Linearity | ±0.25 % of full scale |
| Stroke Measurement Accuracy | ±0.5 % of full scale |
| Stroke Measurement Resolution | 0.002 mm (0.0787402 in) |
Note
Accuracy is measured at a temperature of 23°C (73°F). Maximum stroke rates are at a hydraulic pressure of 203 bar (2,950 psi) ±3 % and an oil temperature of 30°C (86°F).
7.2. Thermal Subsystems¶
The Gleeble 3180 offers a high-speed direct resistance thermal system for heating specimens.
Direct resistance heating provides the ability to reproduce the wide variety of thermal profiles that materials undergo in actual processes. This is critical to the success of thermal-mechanical testing and physical simulation. All Gleeble systems have high-speed heating and cooling rates that can accurately replicate nearly any thermal profile required.
| Characteristic | Specification |
|---|---|
| Heating System Type and Control | Direct resistance with closed-loop control |
| Temperature Controller | Digital closed-loop control using 18-bit ADC and 32-bit digital processor |
| Temperature Range | Room Temperature to 1,700°C (3,092°F) |
| Response Rate | 8,000°C/s (14,400°F/s) |
| Temperature Monitoring Source | Thermocouple |
| Thermocouple Sampling Rate | Twice the Power Supply Frequency (100 - 120 Hz) |
| Resolution | ±1°C or°F |
| Maximum Number of Simultaneous Thermal Channels | 4 thermocouple channels, or 2 thermocouple channels and 1 pyrometer channel |
| Accuracy of Control | ±1°C (in steady state) |
| Accuracy of Measurement | ±2°C or ±1% of temperature (whichever is greater) plus the accuracy of the thermocouple wire (in steady state) |
Note
As the specimen size, diameter, length, or cross-sectional area increases the effective heating rate will decrease.
7.2.1. Thermocouple Wire Types¶
Gleeble systems are capable of recording specimen temperature with various thermocouple wire types. The following types of thermocouple wire can be used on any Gleeble system.
| Part Number | TC Type | Material | Sold As |
|---|---|---|---|
| Operating Range: 0 - 1,450°C (32 - 2,642°F) | |||
| TC005 | R- or S- | Pt 100% | Inch |
| TC006 | R+ | Pt 87% - Rh 13% | Inch |
| TC009 | S+ | Pt 90% - Rh 10% | Inch |
| Operating Range: -200 - 1,250°C (-328 - 2,282°F) | |||
| TC014 | K- | Alumel | Spool |
| TC015 | K+ | Chromel | Spool |
| Operating Range: 0 - 1,700°C (32 - 3,092°F) | |||
| TC017 | B- | Pt 94% - Rh 6% | Inch |
| TC018 | B+ | Pt 70% - Rh 30% | Inch |
| Operating Range: 0 - 750°C (32 - 1,382°F) | |||
| TC030 | J+ | Fe 100% | Spool |
| TC031 | J- | Constantan | Spool |
| Operating Range: -200 - 900°C (-328 - 1,652°F) | |||
| TC032A | E+ | Chromega | Spool |
| TC033 | E- | Constantan | Spool |
| Operating Range: 0 - 2,320°C (32 - 4,208°F) | |||
| TC010 | C+ | W 95% - Re 5% | Inch |
| C- | W 74% - Re 26% | ||
Note
TC wire types C, K, J, and E have a nominal wire diameter of 0.254 mm (0.01 in). TC wire types R, S, and B have a nominal wire diameter of 0.2032 mm (0.008 in).
Note
Gleeble systems can support additional thermocouple wire types not shown. Contact Dynamic Systems for additional information regarding the use of alternate thermocouple wire types.
7.2.2. Heating Rates¶
Heating rates are based on using a 480 V / 150 A power supply, full contact copper grips and, plain carbon steel specimens. See Gleeble Grips for more information regarding the selection of grips.
| Specimen | Free Span | Drawing Number | Maximum Heating Rate |
|---|---|---|---|
| °C/s (°F/s) | |||
| 6 mm dia x 71 mm long | 10 mm | SMR002B | 8,000 (14,400) |
| 10 mm dia x 71 mm long | 10 mm | SMR009B | 1,000 (1,800) |
| 10 mm dia x 15 mm long With non ISO-T Anvils | SMC203B | 50 (90) | |
| 10 mm dia x 15 mm long With ISO-T Anvils | 5 (9) | ||
7.2.3. Cooling Rates¶
Free Cooling Rates
The Gleeble system is able to control the specimen cooling rate based on conductive heat transfer. The efficiency and maximum rate of conductive cooling is directly impacted by grip and specimen geometry, material, cleanliness, and system’s chilled process fluid flow rate.
The controlled cooling rates are achieved using full contact copper grips on 1018 carbon steel specimens. See Gleeble Grips for more information regarding the selection of grips.
| Specimen | Free Span | Drawing Number | Temperature Range | Cooling Rate |
|---|---|---|---|---|
| °C (°F) | °C/s (°F/s) | |||
| 6 mm dia x 71 mm long | 10 mm | SMR002B | 950-800 (1,742-1,472) | 130 (234) |
| 800-500 (1,472-932) | 68 (122.4) | |||
Quench Cooling Rates
Optional quench systems are available which can use compressed air or inert gas to cool the specimen at high rates. A mixture of compressed air and water can also be used in the quench systems for even higher cooling rates.
| Specimen | Free Span | Drawing Number | Temperature Range | Rate |
|---|---|---|---|---|
| °C (°F) | °C/s (°F/s) | |||
| 1 mm thick x 10 mm wide x 100 mm long | 25 mm | SMF002B | 1,000 - 600 (1,832 - 1,112) | 10,000 (18,000) |
| 6 mm dia x 86 mm long | 25 mm | SMR005B | 1,000 - 600 (1,832 - 1,112) | 2,000 (3,600) |
Note
The cooling rates are achieved using full contact copper grips on 1018 carbon steel specimens quenched with water. See Gleeble Grips for more information regarding the selection of grips.
7.2.4. Temperature Uniformity Within the Specimen¶
The Gleeble system has the unique ability to control the temperature uniformity and thus the thermal gradient within the test specimen. Tests can be performed with very uniform temperature within the specimen work zone, equivalent to a furnace-based test, or with the large thermal gradients needed to accurately simulate welding and other processes.
When using Joule heating, the current density in a Gleeble specimen is uniformly distributed across the entire specimen cross-sectional area, meaning that the Gleeble is able to heat the entire specimen simultaneously, from surface to center. Since the Gleeble grips are cool, the heat generated in the specimen will diffuse into the grips, creating a thermal gradient with the ends of the specimen generally being cooler than the center. The severity of the steady state thermal gradient is defined by the rate of heat generated in the specimen, offset by the heat lost to the grips. This gradient can be controlled by utilizing grips of materials with differing thermal and electrical conductivity and contact area. Thermally and electrically conductive grips with a large specimen contact area will be kept cold more readily with the water-cooled jaws, and will accept significant heat from the specimen, resulting in “cold ends” and a very steep thermal gradient.
Grips with smaller contact area and higher thermal resistance will pull much less heat from the specimen. Grips manufactured from material with higher electrical resistance will, themselves, heat under the same current that is heating the specimen. These factors will result in very little heat being pulled from the specimen and a very flat thermal gradient. In some cases the grips or anvils holding the specimen may reach temperatures equal to or higher than the specimen, creating a “reverse” thermal gradient.
When considering Gleeble thermal gradients, it is also critical to differentiate between the axial thermal gradient (along the length of the specimen), and the transverse thermal gradient (across the diameter or cross section of the specimen). Even in situations where a specimen experiences a very high axial thermal gradient, the transverse, or crosswise thermal gradient will be very small. This ability to generate isothermal planes is a critical benefit of the Gleeble. In contrast to furnace or induction heating methods, where the specimen can only be heated on the surface or to a limited “skin depth”, the center of a Gleeble specimen is heated at the same rate as the surface regardless of the heating rate. This ability to generate isothermal planes allows for the Gleeble platform to perform dilatometry and welding heat affected zone experiments at heating and cooling rates relevant to welding and other processes on specimens that are large enough for subsequent mechanical property or toughness testing. This is not feasible on furnace or inductively-heated systems that rely on thermal conduction to heat the center of the specimen. Axial thermal uniformity within a specimen is reported as the difference between the specimen’s center to edge thermal measurements and is dependent upon:
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The following data was obtained using Stainless Steel partial contact grips on 1018 carbon steel specimens. Measurements are taken at steady state temperatures. See Gleeble Grips for more information regarding the selection of grips.
| Specimen | Free Span | Drawing Number | Temperature Uniformity |
|---|---|---|---|
| Lengthwise Thermal Gradient | |||
| 10 mm dia x 111 mm long | 50 mm | SMR023B | ±0.5% of Tavg for 7 mm of midspan |
| Crosswise Thermal Gradient | |||
| 10 mm dia x 86 mm long | 25 mm | SMR012B | ±0.5% of Tavg |
Note
Tavg is the average of the specimen cross section temperature at 1,000°C (1,832°F).
Reproducibility
Thermal gradients in resistance-heated specimens are dependent upon on the properties of the specimen. All specimens with the same physical, mechanical, electrical, and chemical properties will have the same gradients within the accuracy of the thermal system, provided that the specimen grips are in good condition.
7.3. Specimen Size Considerations¶
Gleeble systems are capable of testing a wide variety of material compositions and specimen geometries. Inherent limitations of the system, such as distance between the jaw or anvil faces, the maximum or minimum stroke speed, test temperature, and force limitations for the individual system must be considered when selecting a specific specimen geometry.
The target temperature of a test will also impact the size of a specimen that can safely be tested with a Gleeble system. For example, when considering a standard uniaxial compression specimen, it is possible for a soft material such as aluminum or copper to be tested at ambient temperature. Harder materials, such as steel or titanium alloys, are expected to be tested at elevated temperatures.
The Gleeble 3180’s vacuum tank configuration limits the maximum and minimum specimen geometry that can be tested. A specimen with a maximum of 95 mm free span can be tested in the Gleeble 3180. The minimum free span for the system is 10 mm.
Specimen geometry will vary with any specific test. DSI has identified recommended specimen geometries for commonly performed simulation tests. Please contact Contact Dynamic Systems for assistance identifying a recommended specimen geometry as needed.
Note
To test highly conductive specimens, the system must have adequate water cooling flow per the Site Requirements document. The use of hot grips is recommended for highly conductive specimens. See Gleeble Grips for more information regarding the selection of grips.
7.4. Additional Features¶
Vacuum Tank
One of the distinguishing features of a Gleeble system is the ability to test materials in a controlled atmosphere. Researchers can simulate processes and test specimens in standard atmosphere, in rough vacuum, in high vacuum or in an inert gas environment. This environmental control is possible due to the large vacuum tank, also referred to as a “test chamber,” that is incorporated into every Gleeble. The vacuum tank is fully integrated into the Gleeble system and can be controlled with manual controls or through software controls. A popular approach to atmosphere control in the Gleeble includes “washing cycles” which involve pumping down to a rough vacuum in the tank and then backfilling with an inert gas. This can be conducted multiple times to ensure that the desired atmosphere is achieved.
Most Gleeble vacuum tanks include viewing ports, typically incorporated into the tank doors to allow visual observation of simulations. In some cases, viewing windows are removed or covered to protect users from the light intensity of specimens at elevated temperatures. Depending on the Gleeble model, vacuum tanks may include one or two doors with viewing windows as well as additional ports for measurement devices or equipment feedthroughs.
Feedthroughs are an important feature in the Gleeble vacuum tanks. They allow researchers to install equipment that can measure or interact with the specimen during a test while still controlling the atmosphere. For example, vacuum-sealed electrical feedthroughs allow communication with transducers such as thermocouples, load cells, and strain transducers. Piping feedthroughs enable atmosphere control (e.g. inert gas backfill and vacuum supply) as well as allowing quenching media to be utilized.
Warning
The Gleeble vacuum tank is designed to operate under vacuum or atmospheric pressure, with either air or an inert gas surrounding the specimen. Positive atmospheric pressure, explosive, flammable or corrosive gases, or any mixtures of these gases, should never be used as part of the vacuum tank atmosphere.
Hydraulic Power Unit
The Gleeble 3180 system is equipped with an integrated hydraulic power unit (HPU). The HPU is the primary source of mechanical motion for these Gleeble systems. The HPU is capable of regulating the output pressure of the hydraulic fluid, based on Gleeble system configuration. Typical configurations of the Gleeble allow the user to choose between a high and low output pressure. These pressures can be manually selected with a button on the HMI or through the programming of a Gleeble test. Special configurations of the Gleeble will limit the pressures available for testing. When a low-force load cell is installed, the Gleeble will automatically limit the HPU output to a low pressure. Users will not be able to select a higher hydraulic pressure.
The Gleeble HPU uses one branch of the process fluid chiller for automatic computer control of the hydraulic oil temperature. By automatically regulating the temperature of the hydraulic oil, the Gleeble is capable of maintaining peak performance in a variety of ambient temperature environments. The HPU is protected by a high oil temperature sensor, a high oil level, and a low oil level sensors.
The HPU is enclosed in a self contained cabinet. The cabinet reduces the sound level to approximately 62 dBA with the doors closed. The pump must be located as indicated on the Site Preparation floor plan.
| Characteristic | Specification | |
|---|---|---|
| Pump Motor | 10 hp | |
| Variable Pressure Output | Low Pressure | 68.94 bar (1000 psi) |
| High Pressure | 206.84 bar (3000 psi) | |
| Hydraulic Oil Reservoir | 113 L (30 gal) | |
7.5. Gleeble Physical Dimensions¶
| Equipment | Height | Depth | Width | Weight |
|---|---|---|---|---|
| Control Console | 180 cm (71 in) | 66 cm (26 in) | 61 cm (24 in) | 195 kg (430 lb) |
| 3180 Load Unit | 162 cm (64 in) | 86 cm (34 in) | 196 cm (77 in) | 1,361 kg (3,000 lb) |
| Hydraulic Power Unit with Oil | 165 cm (65 in) | 79 cm (31 in) | 94 cm (37 in) | 907 kg (2,000 lb) |