Engineered Casting Repair Service, Inc.

Presses

3000 Ton Forging Press

The damage was in the upper platen, or crown, of this 3000 ton Lake Erie Forging Press located in Monterrey, Mexico. ECRS was contacted to repair this piece after it had cracked due to fatigue under normal operating conditions. Because of the method of failure, additional strength would need to be added to prevent another failure when it was returned to service.

survey of damages
Cracking was present in two locations on the platen. Both cracks initiated in the same set of casting holes at the top of the piece. Others previously attempted a weld repair on these cracks sometime before ECRS became involved. This proved to be unsuccessful. The total length of crack was approximately 50 inches. This is shown in the pictures below.

repair procedures performed
All of the cracking shown above was repaired using Metalock's® patented repair components. Two masterlocks were installed at one of the crack locations. The pictures below show the installation of these masterlocks. In addition to the masterlocks, metalock® and metalace repair components were installed at both locations. The picture on the right shows the excavated cavities for the metalocks. These procedures were successful in repairing all of the cracks in the platen.

fea analysis
There was an abundant amount of finite element analysis performed when designing the reinforcement for this project. It was decided that the casting holes where the cracking initiated would be eliminated. This was decided when the model originally showed very high stresses at these locations. After eliminating these holes, the model showed to be much more structurally sound. For this reason, it was decided that plugs be fit into these holes and welded completely. This eliminated these high stress areas. The following figures illustrate this.

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The reinforcing strength consisted of plates which were attached to the top of the platen by both bolts and welds. There was a flat plate as well as a vertical rib. The following figures show the effect of the plates on the platen. Notice how much lower the stresses are on the top surface of the platen with the reinforcement installed.

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reinforcement installed
As stated before, this piece failed under normal operating conditions. Thus crack repair alone would not be sufficient to completely repair the platen. For these reasons, ECRS engineers designed a way to reinforce the platen to prevent another failure. This reinforcement included 4 plates which were mounted to the top of this platen. These plates reduce the stresses in the areas of concern by more than 60%. The pictures below show the installation of these plates.

repair complete
The following picture shows the platen when the repair was complete. ECRS is confident that this platen will never fail under normal operating conditions again.

2000 Ton HPM Hydraulic Press

ECRS was contacted when the hydraulic cylinder for the press that you see above developed a crack around the flange at the ram end. This crack had propagated over more than half of the circumference.

survey of damages
The crack developed right in the fillet between the cylinder wall and the flange. This is shown in the picture below. This crack propagated completely through to the inside of the cylinder causing a leak path for the hydraulic fluid.

fea analysis
Finite element computer modeling was used to investigate the cause of this cracking. In the following pictures, you are looking at a cross-section of the plane perpendicular to the cracking. It is very evident in the model that there is a high stress concentration in the fillet between the cylinder and flange. This is no doubt that the cracking initiated at this location on the outside surface of the cylinder.

repair procedures performed
The crack was repaired utilizing metalock® and metalace repair components. By using these components, we were able to restore much of the strength back across the crack plane. Because these components alone were not enough to prevent this problem from re-occurring. Reinforcement was also needed across the crack plane.

reinforcement installed
ECRS engineers designed a reinforcement for this repair using tiebolts. The design was to drill and tap a hole from the flange into the wall of the cylinder, crossing the crack plane. These holes were tapped, and tiebolts were fitted and tightened to a specified torque in these excavations. A diagram of this is shown below.

repair complete

1000 Ton Van Doren Injection Molding Press Cylinder

survey of damages
ECRS was contacted when an axial crack was discovered at the bottom of this hydraulic cylinder. On the outside surface, the crack extended approximately 6", and passed directly through a 1/4" drain hole. This drain hole was is thought to be the initiation point of the cracking.

repair procedures performed
Our repair objectives were to completely stop the leakage of hydraulic fluid and to structurally reinforce the cylinder, allowing it to be returned to service. Metalock® and metalace repair components were used to repair the crack from the inside as well as the outside. The existing drain hole was also bored and sleeved to further assist in the sealing and structural integrity of the area.

installation of reinforcement
A custom clamping band was fabricated at our shop prior to performing this repair. It was designed to fit around the circumference of the cylinder. Specially designed bolts allowed us to tighten this band to a point where the band was almost yielding. This assured us that we were receiving the most possible benefit from the clamping band.

repair complete
After this band was tight, the press was re-assembled and returned to service with no leakage.

2200 Ton Aluminum Extrusion Press Platen

survey of damages
The press repaired was a typical four column extrusion press . The platen of this press was manufactured from cast steel and has a nine-inch(9") diameter extrusion bore. The outboard surface of the platen (the surface that goes into tension during an extrusion cycle). There are also two 6“ diameter casting core holes horizontally aligned in the outboard surface of the platen. Cracking was present from one core hole, across the extrusion bore, and into the other core hole; although, it was not one continuous crack. The outboard surface of the platen is approximately 4" in thickness, and some of this cracking had completely severed it. Below is a sketch of the damage.

repair procedures performed
The crack repair was accomplished by a combination of one(1) preloaded masterlock as well as a series of metalock® and metalace repair components. It was decided that the core holes in the outboard face of the platen contributed to the initiation and the propagation of the cracking. For this reason, we eliminated them by inserting fabricated plugs into these holes. A boss was machined onto these plugs that would be welded into a hole in the reinforcement plate.

FEA analysis
There was an abundant amount of finite element analysis performed when designing the reinforcement for this project. Various plate thicknesses and bolt patterns were analyzed before arriving at the final reinforcement design. The following figures show the effect of the plate being attached to the outboard face of the platen. Notice how much lower the stresses are at the face of the platen with the reinforcement installed.

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installation of reinforcement
The reinforcement was in the form of a three-inch(3") plate which was custom fit to the outboard face of the platen. This plate was attached by a pattern of 48 high strength bolts and the two 3" bosses which plugged the core holes. Holes were cut in the plate to receive the bosses. The bosses were then welded into the plate.

repair complete
Although this repair only needed to last temporarily to allow the plant to operate until the new platen arrived, ECRS engineers are confident that this platen could have remained in operation for many years after this repair.