Analysis of the Automotive Industry’s Demand for Stainless Steel Raw Materials
From a professional point of view, when the attractiveness of imported car prices declines, the sales of domestically-produced cars will likely rise, and the depreciation of the renminbi is expected to create a favorable opportunity for the recovery of car exports. Coupled with the stimulus of the positive markets of Asian exporting countries, China’s auto exports are expected to start to pick up, and the annual export scale is expected to be about 900,000 vehicles.
Domestic car sales may increase from 23,491,900 units in 2014 to 26,194,500 units. As the transportation industry accounts for more than 10% of the downstream consumption structure of stainless steel, the increase in sales will surely drive the demand for raw stainless steel. Zhuo Chuang Information predicts that the consumption of raw stainless steel in the transportation industry will increase from 2.269 million tons in 2014 to 2.317 million tons, while the demand for stainless steel in the automotive sector will increase from 587,300 tons to 654,900 tons.
Since the early 1970s, the amount of stainless steel used in automobiles has increased significantly; after the mid-1990s, the amount of stainless steel used in each automobile has gradually increased from about 10 kilograms in the 1980s to 20-30 kilograms. At present, stainless steel has been widely used in the automotive industry.
According to different application parts, the surface characteristics, mechanical properties and physical performance requirements of stainless steel are also different, which can be roughly summarized into five categories: stainless steel for automobile exhaust systems, stainless steel for automobile fuel tanks, stainless steel for automobile frames, and stainless steel parts for automobiles. Stainless steel for parts and car decoration.
Automotive exhaust system, this part of stainless steel currently accounts for more than half of the total automotive stainless steel applications, and 80% is ferritic stainless steel. With the improvement of the performance of automobile engines, the temperature of the gas discharged by the engine is getting higher and higher.
Therefore, the automobile industry requires the components of the exhaust system to have excellent heat resistance and corrosion resistance, and at the same time to meet the requirements of automobile lightweight. In addition to good corrosion resistance, the end tube material at the rear of the car body should also be beautiful.
The use rate of ferritic stainless steels with low cost, good oxidation resistance, and thermal fatigue properties in automobile exhaust systems will be further expanded, especially ferritic stainless steels containing Nb, which have grown rapidly in Europe and the United States in the past 10 years. With the further improvement of heat resistance and corrosion resistance requirements of automobile exhaust systems, the materials used have also promoted the transition from ordinary stainless steel to higher-performance stainless steel.
Automotive fuel tank, fuel tank steel plate materials must have a variety of excellent properties, including excellent stamping performance, excellent welding performance, high corrosion resistance-internal fuel corrosion resistance, and external corrosion resistance to harsh environments.
Stainless steel is an alternative to steel for automobile fuel tanks in addition to coated plain carbon steel. It is currently used all over the world. In addition to being free from the risk of fuel leakage, stainless steel fuel tanks also have excellent corrosion resistance and good formability, and have the advantage of eliminating or simplifying the painting process, and are also easy to recycle.
Under the influence of stress corrosion cracking and cost issues, the current stainless steel for automobile fuel tanks has been increasingly changed from traditional austenitic stainless steels (such as SUS304L) to ferritic stainless steels, such as ferritic stainless steel 18Cr-1.45. Mo-Ti (trade name JFE-SX1).
Automobile frame, high rigidity is the biggest feature of stainless steel combined frame because stainless steel has good plasticity, toughness, formability, and weldability while ensuring high enough strength and weight ratio. The combination of the modular car frame design and the excellent performance of stainless steel materials can produce a car with particularly lightweight, good impact resistance, high safety and reliability, and long life.
Such a frame can also be completely recycled. At present, South Africa, the United Kingdom, Australia, Belgium, and other countries have successively used 3Cr12 stainless steel to manufacture large buses, coal transport vehicles, urban subway vehicles, and sweepers of various specifications, including large sweepers, sprinklers, and trailers at airports or It is a combination of 3Cr12 and 304L stainless steel, and the service life is generally 15-20 years.
Automotive stainless steel parts, stainless steel is also widely used in various parts. The metal seal ring represented by the stainless steel seal ring has become the main substitute product of the traditional asbestos seal ring. The stainless steel substrate is covered with a metal sealing ring made of rubber. The stainless steel substrate is mostly SUS301, which has the advantages of high-temperature resistance, corrosion resistance, and good elasticity.
In order to improve cooling efficiency and compact structure, some production companies switch to stainless steel plate heat exchangers, and the materials mostly use SUS304, SUS430, and SUS409L. Commonly used stainless steels for automotive fasteners are SUS410, SUS304, SUS316, SUS430J1L, SUH660, etc.
For automotive decoration, the use of stainless steel for interior and exterior decoration materials has a long history, and the scope of use has a growing trend. In order to make the appearance of cars beautiful, manufacturers use stainless steel moldings, antennas, and wheel covers on cars, and stainless steel on handrails, safety rails, and booms of large buses and vehicles.
In order to reduce costs, rearview mirrors are mainly made of SUS430J1L series stainless steel, and some luxury cars use SUS436J1L series stainless steel; car wipers mostly use SUS430, SUS304, SUS301, etc.; headlight guards use SUS430 stainless grade and other steel grades. The safety device on the car also uses stainless steel. For example, the seat belt tensioner uses SUS301 stainless steel, the airbag sensors and booster pump mainly use SUS304 and SUS304L stainless steel, and the ABS induction ring uses SUS434, SUS444, and other steel grades.
The automotive industry has a more comprehensive application of stainless steel. With the expectation that the overall automotive industry is still bright, the demand for raw stainless steel will continue to rise.