The main reason is:
(1) copper alloy corrosion resistance,stainless steel propellor can satisfy the using demand of the propeller in sea water.
(2) of the low melting point of copper alloy, is advantageous for the melting and casting, heat treatment, casting required by the processing can be used.Due to the copper alloy material strength is limited, with the increase of the large-scale and single shaft power of the ship, urgent need higher propeller materials research anddevelopment strength.Replace the copper alloy material of stainless steel screw, paddle material development become a new direction.With the large-scale, high speed of the ship and water pollution, stainless steel as the propeller material seems to be a trend.
It is mainly the advantages of simple introduction is as follows:
1, can be high strength. Under the condition of the same design, compared with copper alloy can be greatly reduced the weight of the propeller, to prevent the stern bearing wear, reduce the rotational inertia of the blade.
2, because of the high strength, large side blade design.Blade can be thinned, and can be made into many paddle, not only make the propeller propulsion efficiency, and to reduce the vibration of the blade, reduces the noise.
3, corrosion fatigue strength and resistance to cavitation erosion performance several times or even more than ten times that of copper alloy, which greatly improved the life of the blade, especially in water pollution, stainless steel has more advantages.
4, with one blade casting respectively, and then welded together can make very large propeller.