3000t forging presses at Haywood Forge
Metalock Engineering Group was asked to give its opinion on the 200mm crack on the crosshead underside of one of the company’s 3000t forging presses at Haywood Forge and was able to offer a metalock cold process repair but with no warranties, due to the crosshead being of cast steel construction.
Somers had already decided to progress with a weld repair and had consulted the Welding Institute for the correct procedure. A prominent welding company was called in and followed all the relevant procedures. However, during the cooling process following completion of the weld, two new cracks appeared on the side of the crosshead from top to bottom.
Metalock Engineering Group was asked to assist with the new problem and devised a metalock repair followed by regular inspections thereafter. Following an NDT inspection the crosshead was marked out for milling to accept “masterlocks” to restore strength to the crosshead. Seven rectangular masterlocks were used, three of which were double masterlocks to provide increased strength. These were located at strategic points across the fractured component. To save time, Metalock Onsite Machining engineers used a portable milling machine for the masterlock apertures and once machined the special steel masterlocks were inserted and secured in place with dowels and studs. Finally the surface was peened and dressed.
To enhance the repair it was agreed at the design stage to fit specially made tie rods. Anchors for these extended the full depth of the crosshead and the nuts for the tie rods were secured by locking pins to prevent movement during forging production.
As a new crosshead had been ordered, Metalock inspected the repaired component on a weekly basis until the new crosshead arrived. However, following its delivery, this was never used, such was the effectiveness of the metalock repair. Eventually, the forging press was sold to an overseas company with the repaired crosshead intact and the new as a spare.
