18. Strip Annealing¶
18.1. Strip Annealing Solutions¶
Annealing and coating lines are large, complex systems that require tight process control and optimization to maintain efficiency and product quality. Simulation data provides insights that enable more efficient scheduling of different material grades, gauges and specifications. This data can be used to reproduce and evaluate existing processes, experiment with process modifications, or troubleshoot problems. Gleeble systems can rapidly and dynamically heat and quench sheet specimens to accurately simulate annealing or galvanizing coating line processing. Simulations and experiments are a safer and less costly method of producing data for optimization. Production line trials risk damaging the mill, take up valuable production time, and often result in wasted material. Unlike expensive mill trials, simulations help staff quickly and efficiently optimize annealing procedures to improve profitability, increase production, and reduce waste by quickly providing the information needed to make better processing decisions.
Annealing simulations offer substantial benefits:
- Better understand the time/temperature relationship of materials, and processing windows
- Improved product quality
- Simulations help optimize material properties and meet the high demands of advanced high-strength steel (AHSS)
- Minimize scrap at transitions and warmer coils and reduce the use of secondary coils or test coils
- Accelerate new product development
- Improve efficiency by defining process windows to allow better transitions
- Develop annealing cycles to meet specifications and salvage off-chemistry or misprocessed coils
- Adjust processing settings for different alloys and grades
Each Gleeble Strip Annealing Simulation Solution includes the following features:
- All Gleeble strip annealing systems utilize an ultra-fast and responsive direct resistance heating system
- Proportional Quench
- A dynamic cooling system with custom gas-quench spray heads that allows fast, yet controlled, cooling
- Complex thermal cycles
- Users can easily program complex temperature profiles, including heating, holding, controlled cooling, reheating and quenching, allowing for accurate process simulation
Large Uniform Temperature Zones - Great care has been taken to maximize the uniformity within the specimen which allows for a more representative post treatment analysis
Environmental Control - Tests can be run in vacuum, air or inert gas
Tension Application - Tension can be applied to the specimen to prevent buckling and simulate roll tension forces
Wide Surface Quenching - Custom designed quench spray heads for air or gas minimize thermal gradients in the test specimen during cooling
DSI offers a range of Strip Annealing Simulation Solutions
General-Purpose MCU - Strip Annealing Kit
The General-Purpose MCU - Strip Annealing Kit fits within the vacuum tank of a Gleeble 3500 or 3800 and is used for heat treatment simulation of specimens. Dynamic temperature control and quenching capabilities enable higher cooling rates with minimal undershoot and a small thermal gradient.
Large-Sample Strip Annealing MCU
The Large-Sample Strip Annealing, available for Gleeble 3500 and 3800 systems, achieves controlled heating and cooling cycles on large sheet specimens with large uniform temperature zones. The sample size is large enough to provide subsequent properties testing of the material, including LDH and tensile test coupons.
Gleeble 525 Strip Annealing System
The Gleeble 525 Strip Annealing Simulator’s low cost, simplicity of operation and small footprint make it an ideal fit for line technicians to use. It can be placed near each annealing line for quick implementation of results. Simple to use, the system can be used to quickly run tests and simulations to help staff quickly make better processing decisions.
18.2. General-Purpose MCU - Strip Annealing Kit¶
Fig. 18.1 General-Purpose MCU - Strip Annealing Kit - DSI# 9505-052.
The General-Purpose MCU - Strip Annealing Kit provides unique methods for physical simulation of strip annealing processes, including continuous annealing and transverse flux annealing.
A Proportional Quench System allows easy programming of cooling rates using only air or inert gas as the cooling medium. The proportional control valve adjusts the cooling gas flow as needed to maintain a linear cooling rate during the annealing simulation. This is the newest method for annealing specimens. It provides simpler programming requirements and more accurate temperature control during cooling. The spray patterns and cooling spray settings must be carefully considered and planned in designing the annealing simulation.
| Characteristic | Specification |
|---|---|
| Maximum Heating Rate | 50°C/s (90°F/s) |
| Maximum Cooling Rate | 400°C/s (720°F/s) with Helium quenching medium and high flow regulator |
| Maximum Temperature | 900°C (1,620°F) |
| Thermally Uniform Hot Zone | 20 mm x 50 mm (0.787 in x 1.968 in) |
| Hot Zone Thermal Gradient | ±15°C (±27°F) |
Note
The maximum heating rate was measured with a 1 mm x 50 mm x 260 mm 1018 carbon steel specimen.
Note
The hot zone thermal gradient is measured at a steady state temperature.
| Part Number | Description | Sold As |
|---|---|---|
| 9505-052 | General-Purpose MCU - Strip Annealing Kit | Kit |
| Optional Accessories | ||
| 59046 | Proportional Quench - 3500 and 3800 GTC systems | Kit |
Note
The General-Purpose MCU - Strip Annealing Kit supports the new Proportional Quench System for better dynamic control of cooling using air or inert gas.
18.2.1. Specimen Size Considerations¶
The specimen used with the General-Purpose MCU - Strip Annealing Kit enables the creation of an ASTM-E8 dog bone shaped sample to be cut out of the thermally uniform center. Contact Dynamic Systems for assistance identifying a recommended specimen geometry.
Fig. 18.2 Strip Annealing Specimen - SMF109.
| Popular Specimen Sizes | |||
|---|---|---|---|
| Length | Width | Thickness | Drawing Number |
| 250 mm | 50 mm | 0.5 mm | SMF119 |
| 250 mm | 50 mm | 1 mm | SMF109 |
| 250 mm | 50 mm | 2 mm | SMF110 |
Thermal Uniformity
Thermal uniformity within the specimen, the difference between the center-point temperature measurement and the edge temperature measurement, is verified by measuring specimen temperature with thermocouples secured onto the specimen.
Thermocouple Placement
All thermocouple location measurements are indexed from the left and top of the specimen. Secure thermocouples at the following locations:
Fig. 18.3 Thermocouple Placement.
Note
All measurements are taken from the left and top of the specimen.
18.2.2. General-Purpose MCU - Strip Annealing Kit Replacement Grips¶
A variety of grips and spray heads have been developed over many years to accommodate the different heating and cooling cycles of different annealing processes. Because of the wide variety of heating and cooling cycles possible in the Gleeble, there is no single grip set which applies to all simulations.
Fig. 18.4 General-Purpose MCU - Strip Annealing Copper Alloy Grips - DSI# GN91101A.
| Part Number | Description | Sold As |
|---|---|---|
| GN9110IAB | Strip Annealing Jaw - Bottom Grip - Copper | Ea. |
| GN9110IAT | Strip Annealing Jaw - Top Grip - Copper | Ea. |
| GN9110IA | Replacement General-Purpose MCU - Strip Annealing Copper Alloy Grips - includes two GN9110AB bottom grips, two GN9110AT top grips, and four spring pins | Set |
Fig. 18.5 General-Purpose MCU - Strip Annealing Stainless Steel Grips - DSI# GN91101.
| Part Number | Description | Sold As |
|---|---|---|
| GN9110IB | Strip Annealing Jaw - Bottom Grip - Stainless Steel | Ea. |
| GN9110IT | Strip Annealing Jaw - Top Grip - Stainless Steel | Ea. |
| GN9110I | Replacement General-Purpose MCU - Strip Annealing Stainless Steel Grips - includes two GN9110B bottom grips, two GN9110T top grips, and four spring pins | Set |
18.2.3. General-Purpose MCU - Strip Annealing Kit Additional Parts¶
| Part Number | Description | Sold As |
|---|---|---|
| 33917 | Moving-Shaft Bolt-Adapter - 5/8-11 in to 3/8-16 in | Ea. |
| 31347 | Moving Shaft Conductor Plate | Ea. |
| OR7025 | Large Moving-Shaft Side O-Ring | Ea. |
| ORS013 | Small Moving-Shaft Side O-Rings | Ea. |
| HZ014 | Specimen Retention Dowel Pin - 3/16 x 5/8 Dowel Pin S.S. | Ea. |
| HI595 | Moving-Shaft Mounting Hardware - 3/8-16 x 2 1/2 in SHCS S.S. | Ea. |
| OR7111 | Fixed-Side O-Rings | Ea. |
| HK361 | Fixed-Side Mounting Hardware - 1/2-13 x 2 1/2 in SHCS S.S. | Ea. |
| HH252 | Hard Stop Mounting Hardware - 5/16-18 x 1 1/2 in SHCS S.S. | Ea. |