Forming Technology of Cold Rolling Square Rectangular Tube and Prospect on New Technology 6

4.5 Prospects For the Development of the New Square Rectangular Tube Technology

As a big manufacturing country, the rapidly developing automobile industry, construction industry, engineering machinery and other industries have increasingly larger demand for section materials, and there are more and more varieties and specifications, the quality of products is also getting increasingly better. Thus, the requirements for cold bending steel are more and more demanding. China's cold bending forming steel industry is facing great challenges and opportunities. It is an urgent task for us to provide section materials with better performance for China's industrial development so as to achieve technological upgrading and transformation of the industry. It is the developing direction of cold bending industry to replace ordinary carbon steel with high-strength steel, extensive section materials with high-precision section materials and simple section materials with complex section materials.

"Early intervention" is an advanced strategic concept, which requires the enterprise not to meet the needs of the upstream customers passively, but to actively intervene the new product development process of the upstream customers, provide the necessary support for the product  manufacturing technology for the customers, and achieve a higher level of cooperation and strategic win-win.

The pursuit of technological progress is one of the measures to continuously improve the core competitiveness of enterprises. Enterprises should be the main body of technological innovation. Adopting advanced and applicable technology that can reduce the investment risk of enterprises and get good technical and economic benefits.

The widespread problems in the square rectangular tube products in China their future development include:

(1) Internal Quality Inspection and Control of Square Rectangular Tubes

Square rectangular tubes meet different quality indicators according to their different uses. For the important parts that bear the force, not only the external quality (size, etc.) but also the internal quality (residual strain control, etc.) are required. At present, on the control of residual strain, some experts and scholars have made use of the simulation of the process of cold bending forming to do the researches on optimization forming technology parameters, which help reduce the residual strain and meet the needs of the subsequent process of the products. Some experts and scholars have also studied the inspection and control of residual strain, and have published some papers. However, there is still no effective and practical engineering inspection and control method in the industry.

(2) High-precision Products and Stable Quality Control

At present, the products of square rectangular tubes in China are still hard to meet the needs of high-precision components in the machinery industry. For some section materials with matching requirements, how to achieve the high-precision requirement under production conditions is a difficult problem for us. It is necessary to start several joints such as equipment, roll die, raw material control, production process control and so on and then systematically solve the problems. The stability tolerance, +-0.1mm, of 75X75 square tube and 100X50 rectangular tube, and the thickness control tolerance, +-0.02mm, have been achieved abroad.

(3) Development and Application of High-strength Steel and New Materials

The application of high-strength steel is more and more extensive, and the yield strength of steel is more and more higher. This is both an opportunity and a challenge for the cold bending industry. The current cold bending section materials are not limited to steel with strength below 500MPa. In the automotive field, the yield strength of cold bending (rolled) section materials have achieved at 1300MPa level in mass production. It is a common technical problem that high- strength steel has large resilience, low plastic elongation and large deformation resistance. Learning from the existing rolling technology in the automotive industry can speed up the development of the cold bending industry.

The continuous emergence of new materials is also an opportunity and challenge for the development of cold bending section steel. The war industry and emerging industries are areas we need to focus on and intervene.