1. The total amount of steel used in suspension springs
The automotive industry uses suspension springs are divided into steel springs and round springs (also known as coil suspension springs) two categories.
Cars use round springs, the use of steel diameter specifications for the 9 ~ 16mm, varieties of cold-drawn steel wire; in addition, some micro-cars, van suspension springs, motorcycle shock absorber springs, etc. also use round springs.
Light trucks, medium- and heavy-duty cars and passenger cars use steel plate springs, the use of size specifications for 6 ~ 30 × 50 ~ 140mm, varieties of spring flat steel. Trucks generally use the same cross-section steel plate springs, heavy-duty vehicles with equal cross-section front springs, rear springs with variable cross-section steel plate springs. Passenger cars generally use variable section steel plate springs. Variable cross-section production is difficult, the country is the only one Dongfeng introduction of British equipment with production capacity.
The development of the automobile industry will determine the use of steel plate springs and round springs. According to statistics, at the end of 2004, nearly 50 enterprises into the suspension spring production of about 500,000 tons, equivalent to about 550,000 tons of spring steel, accounting for 90% of the country's total dosage, so the national automotive suspension spring spring total demand for about 600,000 tons of spring steel, of which spring flat steel demand is about 560,000 tons, spring steel wire in about 40,000 tons.
2. Suspension spring steel consumption
According to the Dongfeng Automobile Suspension Spring Co., Ltd. introduced a 5-ton truck (140 models) front axle steel spring weight of about 50kg, rear axle steel spring weight of about 50 ~ 60kg, the secondary axle (placed above the rear axle) steel spring weight of about 70 ~ 80kg, in addition to the calculation of 90% of the utilization of steel, a total of 5-ton truck, the steel spring demand is about 600,000 tons, of which spring flat steel demand is about 560,000 tons. A 5-ton truck needs a total of 200-300kg steel plate spring.
An 8-ton truck (153 models) front axle steel plate spring weight of about 90kg, rear axle steel plate spring weight of about 90-100kg, the sub axle steel plate spring weight of about 70-80kg, in addition to the calculation of 90% of the utilization of steel, a 5-ton truck needs a total of steel plate spring 300kg or so.
A 13-ton heavy-duty truck needs about 400kg of steel plate spring per vehicle.
Bus to four suspension springs, for example, each vehicle needs an average of about 200 to 300kg of steel springs.
Sedan to four suspension springs (front and rear of each of the two), for example, each vehicle needs an average of about 15kg of spring steel wire.
3. Suspension springs using steel steel steel, specifications and requirements
(1) spring flat steel
Lightweight Trucks, medium and heavy-duty cars and passenger cars use steel plate springs, sub-steel use is as follows:
60Si2Mn on behalf of the specifications: 10 × 60 (65, 75, 90, 100) mm, 11 × 60 (70, 75) mm, the spring square steel specifications for the 18 × 18mm, the annual consumption of about 35% of the total amount of about.
55SiMnB spring flat steel use specifications: 10 × 75mm, 11 × 70 (90) mm, 12 × 70mm, 12 × 90mm, 13 × 70mm, 13 × 90mm, 17 × 70mm, double groove spring flat steel specifications of 10 × 75mm, annual consumption of about 35% of the total amount of about.
50CrVA use specifications 12 × 90mm, annual consumption of about 30% of the total.
In addition, the use of less steel for the 65Mn, on behalf of the specifications of 10 × 75mm, 35CrMnSi on behalf of the specifications of 10 × 75mm, 60CrMnA on behalf of the specifications of 12 × 60mm. plate spring production enterprises also use a small amount of Q235 flat steel and 70 # cold-drawn steel wire, Q235 flat steel used to do the connection of structural components, specifications for 4 × 25mm, 5 × 25mm, 6 × 25mm, 5 × 25mm, 5 × 25mm, 6 × 25mm, 6 × 25mm. 70 # rolled cold-drawn steel wire, cut into fine particles sprayed onto the surface of the heat-treated steel plate to remove the regeneration of iron oxide, steel wire specifications for the use of 1.2mm.
(2) spring steel wire
Suspension springs for cars and some micro-cars, vans, motorcycle shock springs, etc. use of round springs, the steel type 60Si2MnA 55CrSi (SUP12), 50GrVA and other grades.
Sedan **** there are four suspension springs, two each before and after the general diameter of the front is slightly smaller than the diameter of the back of the models used in different diameters, the specification range of ?9 ~ 16mm.
Sedan suspension spring steel wire used in the steel for high-grade spring steel wire, requiring high strength, long fatigue life, good vibration damping and other properties, therefore, on the Spring steel wire chemical composition, the number of inclusions and morphological distribution, surface quality, decarburization layer, microstructure and mechanical properties and other requirements are high. Suspension springs require surface decarburization layer less than 0.5% of the diameter, surface grinding, long fatigue life, tight dimensional tolerances, should be delivered without defects. General use of the usual hot processing method is difficult to meet user requirements, therefore, the car coil suspension spring gradually changed from hot forming to cold forming, after drawing, heat treatment (quenching and tempering to get martensitic organization) made of coiled springs. Suspension spring steel wire development direction is to reduce carbon content, reduce the tendency to decarburization, improve plastic forming properties and resistance to elastic decay and other properties.
4. The main supply of domestic steel manufacturers
(1) the main domestic spring flat steel manufacturers
At present, the annual demand for automobile spring flat steel raw materials is about 560,000 tons, the quality of domestic spring flat steel, varieties and specifications basically able to meet the user's requirements, to the Dongfeng Automobile Sheet Steel Springs Company Limited as an example, the procurement of spring flat steel all localized, the main Purchase Yongtong Steel Co., Ltd, Jiangxi Changli Automobile Spring Co. Now the domestic production of spring flat steel enterprises are as follows:
Jiangxi Changli Automobile Spring Co., Ltd.: located in the eastern suburbs of Nanchang, Jiangxi Province, by Nanchang Iron and Steel Company Limited Liability Company, Jiangxi Automobile Plate Spring Co., Ltd. through the increase in the standardization of the reorganization of the holding subsidiary, at the same time the joint JLM Automobile Group, Guangzhou City, Tian Gao Co. Imported auto parts Co., Ltd **** with the establishment of the joint-stock company, is a member of the China Automobile Parts Industry and Trade Group, is China's auto parts designated manufacturers. The main production equipment introduced from Japan, with an annual output of 60,000 tons of spring flat steel. Single and double groove flat steel specifications for 3 ~ 10 #, flat spring flat steel specifications for (5 ~ 22) × (50 ~ 120) mm, length of 4.8 mm, material 55Si2Mn, 60Si2Mn, 55SiMnVB, 55SiMnoBRe, 50CrVA and so on.
The Xinjiang eight steel: the main products for the production of spring flat steel (including double groove, T-type) series of products, specifications for the 6 × 50 ~ 20 × 100mm, sizing 6 ~ 9m, annual output of about 60,000 tons.
Sichuan Chuan Wei Iron and Steel Group Co., Ltd: the main products are spring flat steel, specifications for the (50 ~ 120) × (5 ~ 30) mm, steel 60Si2Mn, 55SiMnVB, 60CrMnA.
Fushun New Fushun Steel Co., Ltd: the main products for the 6 ~ 25 × 60 ~ 120mm spring flat steel products.
Sichuan Province, Sichuan Province, East Auto Parts Manufacturing Co., Ltd: the main production of automotive steel plate springs, rolled various specifications of automotive spring flat steel, as well as automotive wheel hubs, suspension parts. Annual rolling of automobile spring flat steel 100,000 tons, the production of automobile steel plate spring 30,000 tons.
Shenyang Toyo Steel Co., Ltd: the main products are (6-20) × (80-120) mm spring flat steel, steel 55SiMn, 60Si2Mn.
Daye Special Steel Co., Ltd: the annual production capacity of spring flat steel can reach 100,000 tons.
Zhengzhou Yongtong Special Steel Co., Ltd: the main products are spring flat steel, spring round steel, flat steel specifications from 5-20mm to 50-150mm.
Huaiyang Steel Group: the production of various specifications of spring flat steel, the main material 60Si2Mn, 55SiMnVB, the annual production of 20,000 tons.
(2) the main domestic spring steel wire producers
At present, the annual demand for automotive raw materials for spring steel wire is about 40,000 tons, but the quality of domestic spring steel wire, varieties and specifications are not able to meet the user's requirements, especially for the sedan supporting the higher requirements of the suspension spring wire needs to be imported from abroad, the main importing countries for Japan, South Korea, Sweden and France, etc..
In recent years, Zhengzhou pilot plant, Tianjin Zihua, Changsha Springs, Nanjing Dongwu, Shanghai Yinsong and a number of other enterprises used coil from Japan Kobe, Sumitomo and domestic enterprises such as Baosteel, the use of steel 60Si2MnA, 55CrSi (SUP12), 50GrVA and other grades. Domestic products in terms of quality and Japan, South Korea, compared with similar products there is a gap, but because of the relatively low price, has been provided for some of the spring plant manufacturing micro-cars, van suspension springs, motorcycle shock absorber springs and other parts.
At present, the main domestic alloy spring wire production enterprises for the Baosteel, Shougang special steel mills, Dalian Steel, on the steel plant five four enterprises, Baosteel, on the steel plant has the quality advantage, but the price is relatively higher than the other steel mills. Baosteel high wire plant production of spring steel wire with 55SiCr, 50CrV, 60Si2MnA and other grades, of which 55SiCr spring steel wire drawing, heat treatment and coil spring treatment, has been in Mazda, Chang'an, Santana, Jetta, Fukang and other cars supporting the use.