Extrusion temperature measurement and in process checks

Transcription

1 Extrusion temperature measurement and in process checks Richard Dickson Hydro Aluminum Metals USA Rosemont, Illinois October 25-26, 2016

2 Introduction There is a well know saying in the industry There are three things that are important in Extrusion Temperature, temperature and temperature Temperature management is the key to good extrusion Actually there are three additional things that need to be on this list Temperature, temperature, temperature and temperature

3 Which temperatures matter in the 6xxx process chain 1300 ~1290 F Temperature ( F) ~1076 F 2-3 hrs Extrusion F T solvus Critical temperature range in the process route with respect to the precipitation of coarse Mg 2 Si phase particles 500 ~ 482 F F 5 hrs 100 Casting Homogenization Preheating Cooling Aging Critical time/temperatures Yes it is ALL of them Time

4 What do we rely on Billet oven probes Container one or maybe two thermocouples Exit temperature melt sticks or maybe a pyrometer Aging oven and the cooling on table Luck? There is an old Russian proverb made famous by Ronald Regan Доверяй, но проверяй TRUST BUT VERIFY Interestingly it was also used a lot by Lenin!

5 What do we verify with? Billet oven hand held probe Container??? Maybe an IR camera Exit temperature hand held probe Cooling on table Luck? Thermal treatment ovens surveys?

6 Can we trust our tools? mm - 7 C Temperature deviation ( o C) mm - 21 C 6mm - 40 C Time (s) The most common billet temperature controls T/C is the two prong Sharpness of probes affects the result Probes wear in use and become clogged with Aluminum How often do you sharpen your probes Daily? Each shift?

7 If Billet temperature is not stable each billet is an adventure Die change Unstable billet heating Up and down 35F

8 What can youdo? Make regular manual checks with calibrated device Some people do automatic checks a with pyrometer

9 Verification of billet temperature Advantages of hammer in Speed of application Lack of surface damage Accuracy No probe points to sharpen/maintain Also works well at the press

10 Probe # Probe Name 1 Drill-in Illustration of Type K measuring devises Details 20 gauge thermocouple wire Reference Probe Inserted into billet surface Typical Use Drill-in wire for billet surface, twisted-end thermocouple, general T/C wire gauge 24 gauge thermocouple wire Pound-in wire for billet surface, twisted-end thermocouple, general T/C wire gauge 30 gauge thermocouple wire Pound-in wire for billet surface, twisted-end thermocouple, general T/C wire. 4 Fluke Fluke Calibration thermocouple Use as a contact probe to measure temperature and calibrate an IR handheld Fluke thermometer. 5 Anritsu Anritsu S-221K-01 Temp 1470 F (800 C) max. Accuracy ±2 F Contact probe for generally flat surfaces. 6 Anritsu Fork Anritsu 524K Temp 1290 F (700 C) max. Accuracy ±2 F Used generally for molten aluminum temperature measurement. 7 Hydro Fork Hydro-made probe Offset ±9 F ~6mm tip diameter Hydro Aluminum fabricated contact touch probe. Primarily used for billet temperature. 8 Roller Omega Roller Thermocouple Temp range -420 F to 480 F (-250 C to 260 C) Used for moving profiles (i.e., extrusion runout). 9 Standard Logger Omega Logger Model OM-CP- TC4000 Datalogger to record temperature. 10 Submersible Logger Omega Logger Model OM-CP- TCTEMP1000 Submergible datalogger to record temperature.

11 Verification of exit temperature Melt sticks give a minimum temperature reading Non contact optical pyrometers can give very accurate exit temperature measurements and on line These need occasional verification with a calibrated hand held probe same as billet ovens

12 Other locations for optical pyrometers Some companies use optical pyrometers for; Billet temperature and billet taper measurement Exit temperature measurement Exit of quench measurement Best verified occasionally with handheld probe

13 Verification of quench rates Travel along data loggers Waterproof data logger T/C Clip on to the section Travels through quench and through process to the cold saw Full thermal history of the section I have a design guide if you want a copy just me Richard.Dickson@hydro.com

14 900 Verification of quench rates Travel along data loggers Temperature (deg F) Present Configuration 2nd Configuration Original Configuration 0 0:00:00 0:01:00 0:02:00 0:03:00 0:04:00 0:05:00 0:06:00 0:07:00 0:08:00 (hh:mm:ss) Ideal for minute to below 480 F

15 Verification of aging ovens Temperature surveys thermocouples spread all over the oven load Feb UCL SP LCL Temperature (F) Not achieving temp FAILSASTM 918 standard Time Majority of the locations fail to reach set point. Immediate corrective action.

16 Verification of aging ovens Temperature surveys thermocouples spread all over the oven load 400 Nov 2009 #1 #2 390 #3 #4 UCL SP LCL Temp F #5 #6 #7 #9 #10 # #13 # # Time in hours Fulfils ASTM 918 standard Good thermal management #16 (Controller) Setpoint

17 Temperature verification Vampire type probes have to be sharp and clean Regular (daily) maintenance Exit temperature measurement Optical Pyrometer Verify the reading by hand held checks Submersible T/C data logger can follow whole cooling process Hammer in T/C is a simple and easy to use technique that is also the most accurate TRUST BUT VERIFY

18 Product verification Dimensional tolerances Optical comparator or hand held micrometer Etch the sample to look at welds Compare the location of the weld to the location of the web Give flow balance indications Strength Tensile test TYE Cadillac solution Webster hardness rough check Drift test hollow sections (or flare test) Investigate weld failure to see if good welds

19 Sample 8-1 is the sample located 10 feet from the end of the scrap section. The seam weld here is observed to be of good quality, an observation backed up by a ductile failure of the sample when subjected to flair testing. Good weld

20 Sample 8-10 is the sample located 1 foot from the end of the scrap section. The seam weld here is observed to be of lesser quality, an observation backed up by a brittle looking failure of the sample when subjected to flair testing. Bad weld

21 Trust but Verify