9. Gleeble 540

Fig. 9.1 Gleeble 540.

Over 60 years ago, the Gleeble was developed to study weld heat-affected-zone (HAZ). While Gleeble systems have evolved and grown over time, the new Gleeble 540 Welding Simulator continues to focus on applications necessary for welding research. However, the 540 performs much more than just HAZ simulations, adding a wide range of capabilities including studies of ductility, crack susceptibility, nil-strength determination and much more.

The Gleeble 540 Welding Simulator is built on the new Gleeble 500 Series platform. The 500 Series of Gleeble systems are tailored to provide a compact, economical solution for researchers while retaining the world-class capabilities that have made Gleeble systems the industry standard.

Material Testing Capabilities of the Gleeble 540

Hot Ductility and Hot Tensile Testing on a wide variety of specimen geometries Strain Induced Crack Opening (SICO) Studies Stress vs. Strain Curves Creation Melting and Solidification Simulations Nil-Strength Testing Thermal Cycling/Heat Treatment Simulations Weld HAZ Simulations

Charpy Specimen Heat Treatment Studies Study of Local Brittle Zones Embrittlement and Crack Susceptibility Studies Liquid Metal Embrittlement Studies Welding/HAZ Phase Transformation Studies Creep/Stress Rupture Simulations

The low cost and small footprint of the Gleeble 540 allow it to be placed in laboratories or production environments where larger simulators cannot be installed. The space-saving platform also reduces the weight of the entire system, reducing laboratory facility structural requirements.

The Gleeble 540 features a touchscreen based control systems, making setup and running tests much faster and easier than traditional control systems. Installation and training are simple processes so new users can begin producing actionable data faster than ever before.

Part Number	Description	Sold As
540	Gleeble 540 Welding Simulator	System

9.1. Advanced Gleeble Control

Gleeble 500 Series systems are equipped with advanced Gleeble control systems similar to the Gleeble Touch Control of the 3000 Series systems. The control system of a Gleeble 500 Series system includes an intuitive user display with a large and easy-to-use touchscreen. Advanced software and hardware provide state-of-the-art performance with accuracy and dependability at the heart of the design.

9.2. 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 aluminum framework and structural vacuum tank
Mechanical System	Closed-loop hydraulic servo control
Maximum Force in Compression	30 kN (3,059 kgf, 6,744 lbf)
Maximum Force in Tension	30 kN (3,059 kgf, 6,744 lbf)
Maximum Stroke Rate	200 mm/s (7.87 in/s)
Minimum Stroke Rate	0.01 mm/s (3.94 x 10 -4 in/s)
Maximum Stroke Distance	100 mm (3.94 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).

Maximum Dynamic Force

The maximum dynamic force for the Gleeble 540 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 in the region below the Force vs. Stroke curve. The specifications are not valid for tests conducted outside this operating range.

Fig. 9.2 Force vs. Stroke Velocity.

Hydraulic Servo Response

The Gleeble 540’s servo systems provide the capability to vary the rate of load application in both tension and compression testing. To achieve the system’s rated performance, certain limitations must be observed. For all types of operation, the Stroke rate and Force must be within the operating range as described in the maximum Force vs. Stroke graph.

Fig. 9.3 Time to reach programmed rate.

Fig. 9.4 Distance required to reach programmed rate.

Fig. 9.5 For constant strain rate programs, the duration of the deformation for each hit must be three times the rated response time of the hydraulic servo valve.

Load Cell

The 59002 Load Cell is mounted directly to the stationary jaw. It is used to measure the force exerted on the specimen by the hydraulic system.

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 capacity
Deflection - Full Scale	0.076 mm (0.003 in)
Force Measurement Accuracy	±1.0 % of full scale
Force Measurement Resolution	±0.1 kgf (0.22 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

The 59001 Stroke Transducer is mounted directly to the hydraulic system piston. It is used as the main control transducer for movement of the Pocket Jaws.

Characteristic	Specification
Type	LVDT
Linear Range	±50.8 mm (2 in)
Non-Linearity	±0.25% of full scale
Stroke Measurement Accuracy	0.5 % of full scale
Stroke Measurement Resolution	0.0075 mm (2.95 x 10 -4 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).

9.3. Thermal Subsystem

The Gleeble 540 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 an 18-bit ADC and a 32-bit digital processor.
Temperature Range	Room temperature to 1,700°C (3,092°F)
Response Rate	10,000°C/s (18,000°F/s)
Temperature Monitoring Source	Thermocouple or Optional Pyrometer Control Cameras
Thermocouple Sampling Rate	Twice the power line frequency (100 - 120 Hz)
Resolution	±1°C or°F
Maximum Number of Simultaneous Thermal Channels	8 thermocouple channels
Accuracy of Control	±1°C (in steady state)
Accuracy of Measurement	±1 % of temperature 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.

9.3.1. Thermocouple Measurement Assemblies

The Dual Channel Thermocouple Input series of modules is designed to add thermocouple input channels to Gleeble 500 Series systems and the HDS-V40. Each module may be connected to any available Gleeble PnP port, providing two thermocouple input channels of a given type.

Part Number	Thermocouple Type	Description
59004	K	Dual Channel Input Box
59005	S	Dual Channel Input Box
59006	R	Dual Channel Input Box
59007	B	Dual Channel Input Box
59008	E	Dual Channel Input Box
59014	J	Dual Channel Input Box

Note

A single K-type Dual Channel Input Box is included standard if required.

9.3.1.1. 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.

Note

Each thermocouple wire type requires a corresponding Dual Channel Thermocouple Input Module for temperature measurement in Gleeble 500 Series systems or the HDS-V40.

9.3.2. Heating Rates

Heating rates are based on using a 480 V / 100 A power supply and 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 58.26 mm long	10 mm	SFR002B	10,000 (18,000)

9.3.3. 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 free 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 Type	Free Span	Drawing Number	Temperature Range	Cooling Rate
			°C (°F)	°C/s (°F/s)
6 mm dia x 58.26 mm long	10 mm	SFR002B	950 - 800 (1,742 - 1,472)	140 (252)
			800 - 500 (1,472 - 932)	78 (140.4)

Quench Cooling Rates

The listed cooling rates were achieved using full contact copper grips on 1018 carbon steel specimens. Specimens were water quenched using a 59013 Quench Tanks system and 59024 Standard Quench Nozzle kit. See Gleeble Grips for more information regarding the selection of grips.

Specimen Type	Free Span	Drawing Number	Temperature Range	Cooling Rate
			°C (°F)	°C/s (°F/s)
6 mm dia x 73.26 mm long	25 mm	SFR006B	1000 - 800 (1,832 - 1,472)	6,000 (10,800)
			800 - 500 (1,472 - 932)	10,000 (18,000)
10 mm dia x 73.26 mm long	25 mm	SFR054B	1000 - 800 (1,832 - 1,472)	6,000 (10,800)
			800 - 500 (1,472 - 932)	5,000 (9,000)
11 mm square x 73.26 mm long	25 mm	SFS024B	1000 - 800 (1,832 - 1,472)	6,000 (10,800)
			800 - 500 (1,472 - 932)	3,300 (5,940)

ISO-Q Quench System

The listed cooling rates were achieved using full contact copper grips on 1018 carbon steel specimens quenched internally with compressed air. See Gleeble Grips for more information regarding the selection of grips.

Specimen Type	Free Span	Drawing Number	Temperature Range	Cooling Rate
			°C (°F)	°C/s (°F/s)
10 mm dia x 71.37 mm long	10 mm reduced to 6 mm dia x 6 mm long	SFR203B	950 - 800 (1,742 - 1,472)	250 (450)
			800 - 500 (1,472 - 932)	375 (675)
10 mm dia x 71.37 mm long	10 mm reduced to 5 mm dia x 5 mm long	SFR202B	950 - 800 (1,742 - 1,472)	375 (675)
			800 - 500 (1,472 - 932)	375 (675)
10 mm dia x 71.37 mm long	Hollow center - 3 mm dia through hole	SFR202B Modified	800 - 500 (1,472 - 932)	1,500 (2,700)

Note

The cooling rate of 1,500°C/s (2,700°F/s) using a modified SFR202B specimen is achieved using water. The supply and return hoses of the ISO-Q kit must be positioned on the same side of the specimen to enable smooth flow of the quench water through the specimen.

9.3.4. 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:

Material Thermal Resistivity Electrical Resistivity Grip Contact Surface to Specimen Volume Ratio Specimen Length Specimen Cross Section

Free Span Grip Selection Heating Rate Isothermal Holding Time Interface Resistance

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.

9.4. 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.

Fig. 9.6 Small-Format Round Specimen - SFR115.

The Gleeble 500 Series’s vacuum tank configuration limits the maximum and minimum specimen geometry that can be tested. The maximum specimen length for a tensile specimen is 95 mm. The minimum specimen size should have a free span no smaller than 8 mm.

Specimen geometry will vary with by test type. DSI has identified recommended specimen geometries for commonly performed simulation tests. Contact Dynamic Systems for assistance identifying a recommended specimen geometry as needed.

Popular Specimen Sizes
Specimen Length	Specimen Width	Specimen Thickness	Drawing Number
Specimens
106.2 mm	10 mm dia	N/A	SFR115
58.26 mm	6 mm dia	N/A	SFR002
101.2 mm	6 mm dia	N/A	SFR106
58.26 mm	11 mm Sq	N/A	SFS002
Flat Specimens
100 mm	10 mm	1 mm	SMF002

Note

The use of hot grips is recommended for highly conductive specimens. See Gleeble Grips for more information regarding the selection of grips.

9.5. 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.

Gleeble vacuum tanks include a large viewing port incorporated into the tank door 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.

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 500 Series systems are 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 the Gleeble system configuration. Typical configurations 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.

Hydraulic Power Unit Consumables

Reference Hydraulic Oil for common service parts.

The Gleeble HPU is fully integrated into the 500 Series systems. This means that the system uses a single chilled process fluid supply for system temperature regulation and hydraulic oil temperature regulation. 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, high oil level, and low oil level sensors.

Characteristic		Specification
Pump Motor		5 hp
Variable Pressure Output	Low Pressure	68.94 bar (1000 psi)
	High Pressure	206.84 bar (3000 psi)
Hydraulic Oil Reservoir		38 L (10 gal)

9.6. Gleeble Physical Dimensions

The Gleeble 500 Series systems were designed to fit through a standard entryway. With a depth measuring just 87 cm (34 in), with the Lower Console Assembly removed. The system will occupy a space of 3 x 4 m (9.84 x 13.12 ft) for general operation. This does not include the additional space required for options such as a freestanding vacuum system option.

Equipment	Height	Depth	Width	Weight
500 Series System	125 cm (49 in)	97 cm (38 in)	202 cm (80 in)	800 kg (1,800 lb)

9.6.1. Frame and Machine Stiffness

Gleeble 500 Series systems have a frame stiffness of 3.85 x 10^-8 m/N (6.74 x 10^-6 lbf).