November 18, 2002
Suzuki has developed low-cost, highly temperature-resistant
"vanadium cast steel" to be used for exhaust manifolds.
Suzuki Motor Corporation and Aisin Takaoka Co., Ltd. (based in Toyota City, Aichi, Japan.) have succeeded in jointly developing "vanadium cast steel" which shows better heat resistance than the conventional material *1 by a margin of 50 degrees Celsius. Suzuki is planning to apply this newly developed steel to the Every turbo exhaust manifold *2 from November production.

*1: High silicon ferritic ductile steel with a small amount of molybdenum
*2: A pipe for gathering and ejecting gas at high temperature after combustion.

Automobile manifolds are required to have high temperature resistance because they are directly exposed to exhaust gas shortly after combustion.

Exhaust gas temperatures tend to go up as today’s technology enables higher engine outputs and, in terms of higher heat resistance, austenitic ductile steel or stainless steel should be used instead of the conventional material.

However, steels such as austenitic ductile steel or stainless steel are not suitable for casting or cutting, and the high content of expensive nickel or chrome makes their production cost much higher than the conventional material. A new excellent material had to be developed with a satisfying performance and superior in cost and processing to those more expensive steels.

The conventional material has been developed into the new "vanadium cast steel" with a higher silicon content and some vanadium added in order to improve the high temperature property. This has resulted in improving the high temperature strength more than 1.5 times and the thermal fatigue life is 2.5 times as long under the same conditions. This cast steel tolerates usage in a higher temperature range than the conventional material, which means that it can replace the austenitic ductile steel.

In terms of production cost, that of "vanadium cast steel" is approximately three times lower than materials such as austenitic ductile steel."

Suzuki Motor Corporation will apply this developed material to Every turbo exhaust manifolds from the November production and will successively expand its use.