Problem: Fatigue fracture occurred at the mid-span of the mandrel, resulting in production line shutdown.

Solution: WC-Co coating applied by plasma spraying;Local welding reinforcement.

Result: Repaired mandrel operated normally for 14+ months,Prevented over 3 million RMB in direct losses.

Problem: Surface oxidation wear on mandrel caused tube inner diameter deviation exceeding 0.5mm.

Solution: Laser-clad CoCrW alloy coating (1.2mm thickness) with cryogenic treatment.

Result: The qualification rate of rolled steel tubes increased from 82% to 98% with a repair cost of merely RMB 180,000.

Problem: Fatigue fracture occurred at the mid-span of the mandrel, resulting in production line shutdown.

Solution: WC-Co coating applied by plasma spraying;Local welding reinforcement.

Result: Repaired mandrel operated normally for 14+ months,Prevented over 3 million RMB in direct losses.

Problem: Surface oxidation wear on mandrel caused tube inner diameter deviation exceeding 0.5mm.

Solution: Laser-clad CoCrW alloy coating (1.2mm thickness) with cryogenic treatment.

Result: The qualification rate of rolled steel tubes increased from 82% to 98% with a repair cost of merely RMB 180,000.