Current Status for Domestic Automobiles

                                                                      Current Status and Suggestions of Spring Steel Wires for China Domestic Automobiles

 

1. Domestic automobile development trend

 

With the rapid development of modern science and engineering technology, improving the safety and reliability of automobiles, reducing environmental pollution and energy saving have become the coveted development direction of automobile manufacturers. For this reason, automobile engines are advancing by leaps and bounds in the direction of high speed, high load, low pollution, low energy consumption and light weight. As a result, the requirements for engine valve springs and suspension springs are getting higher and higher, mainly in the following aspects: (1) Excellent load-bearing capacity and fatigue resistance; (2) Good elasticity reduction performance; (3) Lightweight and miniaturization; (4) Multiple varieties and serialization; (5) High cost performance.

 

According to the research analysis and development trend forecast report of China's car industry released by China Industry Research Network, China's car market has a huge space. On the basis of the central government's stimulation of local consumption to promote economic growth, coupled with the increase in public wealth, the increase in the population of townships and towns has continued to promote demand for cars. At the same time, under the background of the steady growth of the national economy, my country’s auto industry will also maintain a sustained growth trend, but the competition in the domestic auto market will become increasingly fierce. With the development of my country’s auto industry and the improvement of the national economy, the Chinese government It will continue to improve and strengthen industry management, guide and promote the development of the automobile industry in the fields of independent innovation capability building, new energy automobile technology research and automobile service industry, so as to realize the historic transformation of my country from a big automobile industry to a powerful automobile industry.

 

2. Types and gaps of spring steel wire at home and abroad

 

The core technology is the main competitiveness of the market, and achieving a strong automobile industry requires technological breakthroughs in the entire industrial chain as a basis. However, my country's current automotive engine technology and some parts of the engine are lagging behind developed countries, and the control of the core technology is basically occupied by international industrial powers. At present, the valve springs, some clutch springs and some suspension springs used in domestic car engines are all made of imported steel wire or processed domestically with imported raw materials.

 

1. Steel grades involved: According to the effect of use in automobiles and the cost-effectiveness of the product, low-alloy spring steel wire rods involve many steel grades, mainly carbon steel series, Cr-V series, Cr-Mn series, Si-Mn series , Si-Cr series, Si-Cr-V series, and more complex series formed by adding a small amount of alloying elements V, Ni, Co, Mo, W, etc. on the basis of Si-Cr series. Mainly representative steel types: 65Mn, 50CrVA, 67CrVA, 55SiCrA, SAE9254V, SAE9254, 60Si2MnA, 60Si2Cr, 60Si2CrA, SRS60, UHS1900, UHS2000.

 

2. Foreign manufacturers: The major foreign spring steel wire rod manufacturers are Japan's Kobe Steel, Nippon Steel, Arcelor-Mittal, German Saarster, British Corus and South Korea's Pohang. The main steel grades are SAE9254V, SAE9254, SRS60, UHS1900, UHS2000, 50CrVA, 67CrVA, SUP7.

 

3. Domestic steel mills: The main domestic spring steel wire rod manufacturers include Baosteel, Xingcheng Special Steel, Shagang, Nangang, Xinggang, Egang, Xianggang, Qinggang, etc. The main steel types are 55SiCrA, 60Si2MnA, 55CrMnA, 55SiCrVA , 50CrVA, 60Si2CrVA.

 

4. Domestic and international gap: Compared with imported spring steel, domestic wire rods are of poor or unstable quality, which is mainly reflected in the following aspects: poor purity, many and deep surface defects, relatively short fatigue life, and unstable mechanical properties ; Decarburization of the surface is difficult to completely avoid; segregation is more serious; the pursuit of product quality is low; the quality of after-sales service is poor.

 

3. Reasons for the gap

 

1. Due to the late start of my country's automobile industry, the development of its related supporting industries was late or slow. At the same time, independent research and development capabilities are poor, research and development funds are insufficient, research and development risks are high, and the enthusiasm for research and development of new steel grades with high technical difficulties is not high.

 

2. Nowadays, major steel mills have special requirements for new steel grades or market demand (such as oil quenched-tempered spring steel wire is now tending to ultra-high-strength transition, which belongs to the current special requirements) steel research and development capabilities and R&D strength, but due to factors such as the physique of the steel plant or business strategy, the steel plant is aiming at production capacity or profitability, and there is little support for the research and development of steel grades with small market capacity, let alone the improvement of its quality. As a result, the research and development of new steel grades or special requirements steel is stagnant or slow;

 

3. The implementation of production, education and research is out of line or the implementation is not fully implemented. There is too much pursuit of commercial interests between scientific research units and steel mills, while the pursuit of continuous optimization and improvement of quality is ignored or discarded, which violates the original intention of combining production, education and research. Can achieve continuous and rapid quality improvement, so domestic spring steel can only stay in the international low-end list;

 

4. Domestic scientific research units, steel mills, processing and manufacturing units, spring manufacturing units, and users have not established a complete and effective industrial chain. At the same time, steel mills still have poor after-sales service quality, resulting in the ineffective collection of quality information from downstream customers. The industrial chain is not sound, and the quality information collection channels are not smooth. Where is the direction for the improvement of steel mills and research orders? Where is the motivation? So it created a deep-rooted concept of "just use it", which shows that it is not that the quality cannot keep up, but that the concept does not change.

 

Four, technology improvement, research and development suggestions

 

Domestic low-alloy spring steel wire rods have a long way to go to catch up with the advanced level of developed countries in terms of physical quality and variety, but they are not unattainable. With the current domestic technical strength and the advanced equipment of some steel plants, it should be able to catch up with or exceed the level of developed countries.

 

1. my country has now become a major automobile production country, and there is huge domestic and international market space, but my country's core automobile manufacturing technology and international brand competition are far behind. Therefore, relevant departments are required to provide strong support for the research and development of automotive core technologies and related parts, especially for scientific research units and researchers, as well as research and development units of new steel grades with high technological content but small market capacity or steel with special requirements. stand by. At the same time, they are regulated and controlled, while stimulating units or individuals to conduct independent research and development, so as to supervise and enhance the international competitiveness of the brand.

 

2. Relevant departments will come forward to coordinate the establishment of a joint industrial chain to change the original industrial chain situation of "self-centered and independent". The industrial chain can start with the research and development and production of the valve spring steel-55SiCrA ultra-pure wire rod, and unite with the research and development units in the industrial chain or steel mills, steel wire plants, spring plants, OEMs and automobile manufacturers to form a complete research chain , Establish a research and development mechanism that shares benefits and risks, keeps steady, gradual progress, and runs in small steps before success is possible.

 

3. The governing department of the iron and steel industry should advocate, promote and encourage R&D units or steel mills and other affiliated industrial chains to learn their ‘craftsmanship spirit and pursuit of high-quality production management concepts’ from Germany, Japan and other countries. People's ideological management concept does not change, no matter how strong the technical team, no matter how good the process equipment, it is difficult to produce continuous and stable high-quality products, so ideology determines success or failure. Furthermore, the industry should strictly formulate national standards for special-purpose steels (such as 55SiCrA ultra-pure wire rods), move closer to or refer to European standards, and use standards to restrict or promote technological transformation and quality improvement of steel plants.

 

Low-alloy spring steel wire for automobiles is an indispensable key material in the automobile manufacturing industry. The most important part of its use is the engine valve spring. The low-alloy spring wire produced in my country is currently hardly used in international brand cars. This is worthy of reflection and awakening by relevant domestic industries, relevant scientific research units and major steel mills, and immediately adjust their thinking to accelerate the development and quality improvement of low-alloy spring steel wire rods or other wire rods for automobiles. It is the icing on the cake for my country's auto manufacturing industry or auto parts manufacturing industry, and can occupy a place in the international brand competition.