About:

 The exhaust manifold is connected with the engine cylinder block, and the exhaust gas of each cylinder is concentrated into the exhaust manifold, with divergent pipelines. The main requirements for it are to minimize exhaust resistance and avoid mutual interference between the cylinders. When the exhaust is too concentrated, the cylinders will interfere with each other, that is, when a cylinder exhausts, it just encounters the exhaust gas that is not discharged from the other cylinder. In this way, the resistance of the exhaust will be increased, and the output power of the engine will be reduced. The solution is to make the exhaust of the cylinders as separate as possible, one branch per cylinder, or two cylinders one branch, and make each branch as long as possible and shaped - to reduce the mutual influence of gases in different tubes. In order to reduce exhaust resistance, some racing cars use stainless steel tubes to manufacture exhaust manifolds.

 Functions:

 1. Stable microstructure

 In the range from room temperature to operating temperature, the material should undergo phase transition as little as possible or as little as possible. Because the phase change will cause a change in volume, so that it produces internal stress or deformation, affecting the performance and life of the product. Therefore, the base material is a stable ferrite or austenitic structure. The damage form of cast iron parts working under high temperature conditions is mainly displayed as corrosion under high temperature conditions, after the oxidation of the component phase in the organization (such as graphite carbon), the volume of the oxide is greater than the original volume, causing irreversible expansion of the casting. Compared with sheet, vermicular and spherical graphite forms, the cast iron of spherical graphite has better high temperature resistance, because the graphite in each eutectic mass forms a continuous branched three-dimensional form during the solidification process of cast iron to the end of eutectic solidification. At high temperature, when oxygen invades the metal, the graphite is oxidized to form a microscopic channel to accelerate the oxidation process. When spheroidal graphite nucleates, it grows to a certain size alone and is surrounded by the matrix to exist as an isolated ball. After the graphite ball is oxidized, it will not form a channel, thus weakening the further oxidation. Therefore, the high temperature oxidation resistance of spheroidal iron is better than that of other forms of graphite, and the oxidized holes have little effect on the high temperature strength of cast iron than that of other forms of graphite. Creep ink is somewhere in between.

 2. Low cost

 There are many types of heat and high temperature resistant metal materials, but because of the complex shape of the exhaust manifold, the materials used to manufacture the exhaust manifold need to have good processability, and its cost needs to meet the needs of the mass production of the automotive industry.

 The above content is organized by Jiangsu stainless steel pipe manufacturer.