Ball Mill Shaft- Journal Bearing Area HVOF Coating Issue
02-02-2023, 06:44 PM,
#1
Pencil  Ball Mill Shaft- Journal Bearing Area HVOF Coating Issue
Dear forum

We've serviced Ball Mill's shaft bearing area with HVOF coating and we failed. After 1-2 days of running, the coating was peel off and had many blisters all over the shaft area. (See picture)
Now, with hydrodynamic bronze journal bearing system, it should not be any impact on coating during operation. But, it is an ideal situation. When we disassembled the journal bearing from the shaft, we saw bronze color adhered on the shaft surface as in the pictures. Anyone know what's going on ? In the end we have to grind HVOF out and undersized the shaft. Under HVOF coating we have arc spray coating with Ni5Al with a thickness of 0.2mm on 3 different locations along with the shaft material itself (See final result). And that's the final surface that works just fine. Now the customer have been operating the Ball mill for months with no problem. Here are some details.

Ball Mill specifications:
Type: Overflow Ball Mill
Weight: Ball Mill = 50 Tons, Ball steels and products = 50 Tons. Total = 100 Tons
Journal Bearing: Bronze hydrodynamic journal bearing
Repairing area: Dia. 1070mm x L 460mm

Thermal Spray specifications:
Coating process: HVOF Coating
Coating Material: Ni20Cr as bond coating + SS420 for top coat (0.2mm)
Grinding and polishing
(Underneath coating on 3 different locations: Arc spray with Ni5Al 0.2mm) 

Please advice

Best regards
Reply




Possibly Related Threads…
Thread Author Replies Views Last Post
  HVOF T800 Tensile Bond Strength issue wgg237 3 6,674 09-11-2023, 09:18 AM
Last Post: Sail L
  Spark Issue on DJ2600 HVOF Flame xxxxmgulkokan 3 2,529 08-31-2022, 03:15 PM
Last Post: Red Baron
  Arc spray or HVOF for bearing of turbine generator shaft Youssef 0 2,283 06-15-2020, 06:08 AM
Last Post: Youssef
  HVOF coating on bronze bearing housing demionkrishan 4 3,379 01-16-2020, 09:43 AM
Last Post: demionkrishan
  Chrome-Carbide coating issue DanyGans 11 11,366 10-08-2019, 05:19 PM
Last Post: Lemster68
  Roller bearing KevGarty 2 3,199 02-07-2018, 09:43 PM
Last Post: demionkrishan
  Propeller shaft repair by flame spray in the cones area Iwan Sedaryawan CA 1 3,387 12-09-2016, 04:56 AM
Last Post: Stephen Booth
  Crankshaft bearing coating Met.Eng. 0 3,453 11-09-2015, 08:23 PM
Last Post: Met.Eng.
  HVOF DJ2600 DJ8W powder feeder issue vetrinit 5 9,037 06-17-2015, 04:39 PM
Last Post: loriolo
  ball valve and gate valve coating Jaydev 2 6,048 01-29-2015, 05:06 PM
Last Post: IgorGarcia
  Journal rebuilding shantanu 7 7,856 11-20-2014, 11:29 PM
Last Post: loriolo
Rolleyes Calculate powder weight needed to spray surface area Zacadoom 2 9,500 11-10-2014, 02:58 PM
Last Post: Zacadoom
  Coating on shrink fit bearing journals shantanu 1 3,995 01-27-2014, 07:44 AM
Last Post: Vijay Deshpande
  HVOF SPRAY ON EN31 BEARING STEEL SHAFTS Zanitech 1 5,063 10-18-2013, 11:49 AM
Last Post: Stephen Booth
Information Hydraulic Shaft - Thermal Spray - Advice needed Jagdeep 2 5,419 10-09-2013, 07:16 PM
Last Post: shantanu



Users browsing this thread: 1 Guest(s)





Surface Engineering Forum Sponsor - Alphatek Hyperformance Coatings Ltd