Sumitomo Metals Completes Development of Three-Dimensional Hot Bending Quench Mass Processing Technology

Sumitomo Metal Industries, Ltd. (Sumitomo Metals), Sumitomo Pipe & Tube Corporation, and Sumitomo Metal Plant Co., Ltd. have been developing three-dimensional hot bending and quench (3DQ) technology, an innovative technology that contributes to reducing the weight of vehicles. We have now completed development of 3DQ mass processing technology. For the first time in the world, automobiles that have the parts manufactured with this 3DQ technology will be for sale by this September.

3DQ technology is the continual process of steel tubes with diverse shapes (round, square, and various different shapes) to be heated and sequentially quenched with cooling water as they pass through the manufacturing line. By using this technology, high-tensile strength steel tubes with complex bended shapes can be manufactured without using dies. High-tensile strength of 1470 MPa or more, a level that conventional processing methods such as cold bending and hydroform bending could not realize, can also be achieved. In addition, our new mass processing technology uses robots for bending in order to make the facility compact and reduce costs. The robot technology has been jointly developed with Yaskawa Electric Corporation.

                           Three Dimensional Hot Bending and Quench (3DQ) Mass Processing Technology

At present, the common practice in manufacturing an automotive body is cold stamping of steel plate. It has been known that if an automotive body could be manufactured from steel tubes, rigidity against bending and torsion would be enhanced to enable the creation of a light-weight, safe automotive body. However, given the difficulty in processing steel tubes with high-tensile strength, the maximum high-tensile strength achieved was 980MPa. Another problem has been processing the tubes into complex shapes. While aluminum components with a closed cross-section structure have been commercially used, their adoption in mass-produced cars has been limited due to high costs.

3DQ technology is revolutionary in enabling highly efficient manufacturing of steel tubes with high-tensile strength in complex shapes. Application of this technology reduces the weight of automotive parts by up to 50% and enables the manufacture of light-weight, strong, and safe automotive bodies at low cost. This has the potential to drastically change the whole concept of the car body in the future.

Together with Sumitomo Pipe & Tube, Sumitomo Metal Plant, and Yaskawa Electric, we will strive to advance the technology and expand its application in cooperation with automakers and other customers.