Continuous Annealing Line
Problem
Hot rolling is a mill process which involves rolling the steel at a high temperature (typically at a temperature over 1700° F), which is above the steel’s recrystallization temperature. The hot metal is passed between two rolls to flatten it, lengthen it, reduce the cross-sectional area and obtain a uniform thickness. To maintain quality of the rolls it is imperative that the surface of roll in contact with sheet should have no oxide scaling or protrusion due to high temperature galling. Wear marks on the roll barrel could affect the operation and also deteriorate the quality of the sheet. Once the rolls are worn out the entire line needs to be shut down and the worn out rolls are replaced with new ones. This severely affects the productivity of the plant and increases the downtime and maintenance cost. The line comprises of a set of rolls installed at different sections each subjected to varying loads and temperature.
Solution
High Temperature Wear and Abrasion Resistant Coating Solutions for Furnace Rolls
Our carbide and cermet based coatings provide excellent wear and abrasion resistance at high operating temperatures. These coatings are deposited with robotic controlled HP-HVOF process which produces a dense and homogeneous coating and sealed with a indigenously developed ceramic sealer which creates an impervious barrier designed to sustain high temperatures. The finish coating thickness and surface roughness are very critical for proper functionality of the roll. We have automated processes to ensure these parameters are achieved as per customer requirement.
We have been supplying PIC DC12, PIC D34 and PIC D36 coated rolls to renowned OEM’s and End users for many years. We have in-house capabilities for complete manufacturing and supply of coated rolls up to 1500mm diameter and 6000mm length.
We offer three variants of coating based on the different operating temperatures. These are high temperature oxidation resistant MCrAlY and CoCrAlY based cermet coating. However the correct composition selection and proportion of these powders and the spraying technique is what differentiates us from our competitors. Our coatings have been approved by renowned international OEM’s and have outperformed on numerous occasions for furnace roll applications.
| Coating Properties | PIC DC12 | PIC D34 | PIC D36 |
|---|---|---|---|
| Micro Hardness (HV0.3) | 800 - 1100 | 800 - 1100 | 800 - 1100 |
| Max Temperature | < 850°C | < 1000°C | < 1150°C |
| Bond Strength | >10000 Psi | ||