With the continuous development of spring application industry, the requirements for springs are getting higher and higher. For example, when the railway is speeding up and the freight car is overloaded, the buffer spring requires good performance to meet the requirements of "speeding up" and "overloading" of the train. Therefore, new requirements are put forward for spring steel. From the development trend, the requirements of spring on mechanical properties, fatigue properties, elastic resistance, physical and chemical properties and technological properties are getting higher and higher. Therefore, Wuhan Iron and Steel Co., Ltd. of Shanghai Baosteel Group cooperated with Iron and Steel Research Institute to carry out the experimental study on mechanical properties and rotary bending fatigue of spring steel for speed-up railway. The fatigue test of cylindrical helical spring is carried out in cooperation with North Jiaotong University. Through scientific and technological research, WISCO has successively provided spring steel samples for speed-up railways for locomotive and rolling stock factories in Qiqihar, Guiyang, Xi, Tianjin, Jinan and Zhuzhou. Large-scale and super-long railway spring steel silver bright strip is also developed to meet the needs of passenger car speed increase.
The newly-built oil quenching and tempering production line for suspension spring steel wire invested by Shanghai Second Iron and Steel Company has an annual production capacity of 10000t. At present, the production line has been put into trial production, and the high-stress oil quenching and tempering suspension spring steel wire has been successfully developed. This kind of domestic spring steel wire is mainly used for springs with high fatigue resistance and high relaxation resistance, such as suspension springs of cars, mini-cars and high-grade motorcycle damping springs. This will greatly promote the localization rate of automobiles in China. At present, Shanghai No.2 Iron and Steel Company has put the domestic automobile tempering suspension spring steel wire on the market, and the varieties and specifications are relatively complete, including 55CSi, 60Si2MnA, 60Si2Cr, 65Mn and so on. And organize production in accordance with international standards to replace imports.
"Spring steel for passenger cars and railways" successfully developed by Jiangsu Xigang Group Company was included in the national torch plan project in 2003. It is understood that the spring steels developed by Xigang Company mainly include 60Si2MnA(T), 60Si2CrV(A), 60Si2CrA and 50CrVA, which are mainly used in railway and automobile manufacturing.
China's huge spring market has attracted the attention and optimism of foreign businessmen. It is reported that recently, the world-famous manufacturer of high-strength induction heat-treated suspension spring steel wire (rrw), Japan Gaozhou Hot Refining Co., Ltd., will set up a joint venture with Shanghai Automobile Co., Ltd. and Japan Meidawang Company, with an investment of/kloc-0.50 million US dollars, to research, produce and sell steel wire and other metal products for shock absorbers of automobiles and motorcycles, so as to meet the increasing quality requirements of spring steel in the domestic automobile industry. It is estimated that by 2006, the annual production capacity of the joint venture will reach 14400 tons. According to the market forecast of the joint venture company, by 20 10, the output of China cars will reach 4.4 million, and 40,000 tons of suspension spring steel wire will need high-intensity induction heat treatment, and its products will occupy more than 60% of the China market, ranking first in the industry.
Due to the accelerated development of the spring industry in China, the spring market is constantly expanding. Similarly, the prospect of domestic spring steel market is expanding day by day, but its competition will be more intense. How to occupy the domestic spring steel market is a major issue.