Feed Screw Root Coating
For Plastic Extrusion & Injection Molding Feed Screws
Specialized alloy coatings for root diameters, utilizing Flite Technology's PLASMA-BOND welding system. Excellent bond strength and virtually no heat build up on screw. Eliminates distortion and other problems associated with conventional welding methods.
Now feed screw with sever root damage, heavy scoring and abundant pitting can be sectored to original tolerances and finishes. We can also reclaim worn screws that were rebuilt several times or subjected to improper polishing during rebuilding. Part or all of the root diameter areas can be coated.
Korgard, our most popular repair alloy, is also chrome platable. Root coatings for use under extreme abrasive and corrosive conditions are also available. Standard screw base material ex. 4140 often lacks the properties for substantial longevity in these situations.
Listed below are a few of these coatings with comparative property data.
Specialized alloy coatings for root diameters, utilizing Flite Technology's PLASMA-BOND welding system. Excellent bond strength and virtually no heat build up on screw. Eliminates distortion and other problems associated with conventional welding methods.
Now feed screw with sever root damage, heavy scoring and abundant pitting can be sectored to original tolerances and finishes. We can also reclaim worn screws that were rebuilt several times or subjected to improper polishing during rebuilding. Part or all of the root diameter areas can be coated.
Korgard, our most popular repair alloy, is also chrome platable. Root coatings for use under extreme abrasive and corrosive conditions are also available. Standard screw base material ex. 4140 often lacks the properties for substantial longevity in these situations.
Listed below are a few of these coatings with comparative property data.
| Chemical Compositions | ||||||||||||
| Alloy | Cr | C | Si | Mn | Mo | Fe | Ni | Co | B | W | Others | |
| Cobalt-Base | ||||||||||||
| FTPB-60 | 28 | 1.1 | 1 | 1* | 1* | 3* | 3* | Bal | -- | 4 | -- | |
| Intermetallic Compounds | ||||||||||||
| FTPB-400 | 8.5 | 0.08* | 2.6 | -- | 28.5 | -- | -- | Bal | -- | -- | Ni+Fe=3* | |
| FTPB-700 | 15.5 | 0.08* | 3.4 | -- | 32.5 | -- | Bal | -- | -- | -- | Co+FE+3* | |
| FTPB-800 | 17.5 | 0.08* | 3.4 | -- | 28.5 | -- | -- | Bal | -- | -- | Ni+Fe=3* | |
| +Major elements only *Maximum **Includes Ni | ||||||||||||
| Comparative Average Hot Hardness Diamond Pyramid hardness (DPH), kg/mm2 | ||||
| Test temperature, degrees F (degrees C) | ||||
| 800 | 1000 | 1220 | 1400 | |
| Alloy | (427) | (538) | (649) | (760) |
| FTPB-60 | 300 | 275 | 260 | 185 |
| FTPB-400 | 605 | 585 | 585 | 335 |
| FTPB-700 | 540 | 510 | 410 | 245 |
| FTPB-800 | 555 | 555 | 500 | 295 |
| FTPB-150C | 190 | 185 | 170 | 145 |
| Comparative Average Abrasive Wear Data* | ||
| Alloy | Volume Loss (mm3) | Wear Coefficient** |
| FTPB-60 | 66 | 13 x 10-4 |
| FTPB-400 | 29 | 7 x 10-4 |
| FTPB-800 | 18 | 4 x 10 10-4 |
| FTPB-150C | 105 | 12 x 10-4 |
| FTPB-700 | 51 | 13 - 10-4 |
| *Tested for 200 revolutions at a load of 30 lbs (13.6 Kg) using a 9" (229mm) diameter rubber wheel and dry sand.
** Wear coefficient (K) is calculated from V = KPL/h, where V = wear volume in mm3, P = load kg; L = sliding distance in mm: and High h = diamond pyramid hardness. A combination of a low wear coefficient and High hardness is desirable for good wear resistance. | ||
| Comparative Average Adhesive Wear Data* | |||
| Volume loss (mm3) | |||
| Alloy | 90lb. load (40.9kg) | 150lb. load (68.2kg) | 210lb. load (95.5kg) |
| FTPB-60 | 1 | 2.6 | 9.5 |
| FTPB-400 | 0.70 | 1.28 | 2.35 |
| FTPB-700 | 0.07 | 0.09 | 0.19 |
| FTPB-800 | 1.24 | 1.67 | 1.91 |
| FTPB-150C | 0.3 | 0.4 | 2.3 |
| *Average of two or more tests in air against a case-hardened SAE 4620 steel ring (Rockwell C-63). Ring is rotated at 80 rpm. Total sliding distance is 2.2 x 105 mm. | |||
| Comparative Corrosion Data* | ||||
| Media, concentrations and temperatures | ||||
| Alloy | 30% formic acid, 150ºF (66ºC) | 30% acetic acid, boiling | 5% sulfric acid, 150ºF (66ºC) | 65% nitric acid, 150ºF (66ºC) |
| FTPB-60 | 1 | 1 | 1 | 4 |
| FTPB-400 | 2 | 1 | 2 | 4 |
| FTPB-700 | 1 | 1 | 1 | 3 |
| FTPB-800 | -- | 1 | 2 | -- |
| FTPB-150C | 1 | 1 | 1 | 3 |
| *Five 24hr. test periods. Determined in laboratory tests. Samples should be tested under actual plant conditions. Code: 1 = less than 5 mpy (<0.13 mm/y) 2 = 5mpy (0.13mm/y) to 20mpy (0.51mm/y) 3 = more than 20mpy (>0.51 mm/y) to 50mpy (1.27 mm/y) 4 = more than 50mpy (>1.27 mm/y) | ||||
| Comparative Average Charpy (Un-notched) Impact Strength* | ||
| Alloy | ft. lb. | J |
| FTPB-60 | 17 | 23 |
| FTPB-400 | 3.5 | 4.1 |
| FTPB-700 | 2 | 2.7 |
| FTPB-150C | 20 | 27.1 |
| *Undiluted deposits tested at room temperature Tungsten root coatings are also available, plus other coatings for dimensionally changing root diameters. | ||