Spring steel wire is the main raw material of spring, and its quality mainly determines the quality of the final product. The unconventional development of China’s automobile industry not only provides rare development opportunities for the spring manufacturing industry, but also creates a market pull for spring raw materials. The development of spring technology will inevitably raise higher and higher requirements for their raw materials. The spring industry hopes that the domestic metal product industry will keep pace with the times and propose more high-quality and low-cost materials for spring production.
From the perspective of users of spring steel wires, there is still a big gap between domestic spring steel wires and similar foreign products.
A. Steel wire raw material quality Baosteel is a leading domestic enterprise, but compared with the famous Kobe Steel, there is still a gap in bloom technology, harmless treatment of inclusions, and uniformity of overall materials.
B. Production of variable cross-section materials for suspension springs and oval-shaped cross-section materials for valve springs. Domestic companies have no ability to produce them and can only give up the market.
C. In terms of mechanical properties, the strength range of the same batch of domestic steel wire materials, even the same disk material, fluctuates greatly, which makes it difficult to control the outer diameter, free length and shrinkage of the spring during production. The stability of mechanical properties of imported steel wire is obviously better than that of domestic steel wire.
D. Steel wire products foreign companies have used peeling and eddy current flaw detection technology, most domestic steel wire manufacturers do not have the corresponding equipment, or the testing technology is not enough.
E. The two indexes of surface defects and decarburization, which have the greatest impact on the fatigue life of the spring, cannot reach the level of similar foreign products.
F. The development of new steel grades is the weakest link for domestic enterprises. So far, the development of new suspension spring materials and ultra-pure valve spring materials is still blank, and there is no development plan in the near future.