World’s longest stempost casting produced

On June 13, Ansteel Cast Steel Co. Ltd announced that the stempost parts produced for the world’s largest container ship of 22,000 containers have been cast and welded at the Jiangnan Shipyard in Shanghai. The stempost also has set a world record: 15 meters long, 2.9 meters wide, and with a curved arc of 3 meters.

The stempost is the front-end component of the hull. Because it is located at the bow of the ship, it plays the role of cleaving through the waves and navigating, which is required to have sufficient rigidity and strength, as well as a good configuration.

The design and manufacturing team of the stempost castings calculated the reasonable anti-deformation by computer simulation of the stress shrinkage before casting, so the size of each rough part was accurate.

During heat treatment, the infrared ray level is used to correct the level of the casting. Multi anti-deformation support points are designed based on simulating of the deformation trend to ensure the levelness of the casting. CNC is used to ensure that the curved surface arc conforms to the hull, and the three-dimensional scribed line is to ensure the position of the inner ribs. In the post grinding, the casting is leveled by using special supporting iron, and the partial deformation adopts cold orthopedic modification to ensure the straightness during the subsequent heating air-gouging grinding.