14 Purpose the suitable type of stainless steel for the foll

14. Purpose the suitable type of stainless steel for the following application requirements?

Solution

App 1:

Sandvik Springflex SH is a duplex (austenitic-ferritic) stainless steel. It has the following Properties.

Chemical Composition(%):

App 2:

I recommend JFE Steel which is a ultra-high tensile strength steel series with a Tensile strength from 780 MPa to 1470 MPa with excellent formability and weldability which reduces weight and increases safety in collision. These ultra-high tensile strength steels are developed by continuous annealing and water-quenching process which reduce alloy elements in the steel. The TS1180 MPa steel has high elongation and expands 1.5 times larger than the ordinary steel and angeability has also been achieved. It has remarkable work-hardenability and bake-hardenability also. This type of ultra-high strength steel is applied in safety reinforcing parts such as bumper reinforcing materials, door impact beams etc.

App 3:

Colisbro is a high copper alloy steel with minimum additions of silicon and nickel, which are combined to improve the hardness, strength and wear resistance of the material even while retaining many of the physical benefits of copper. These steels are developed by combining heat treatment and cold working process with addition of the ageing process/heat treatment, forming a nickel silicide precipitate that results in metal matrix hardening thus Colisbro has a very higher strength and resistence when compared to many low alloy steels and stainless steels. It also has a yield strength that is equal to 90% of its ultimate tensile strength meanwhile retaining a good level of ductile properties.

The completely age-hardned Colisbro has an excellent wear resistance, excellent bearing properties, a high hardness level, and good anti-friction properties particularly under high loading against hardened steels. The increased level copper content of the alloy ensures that it maintains a very attractive thermal and electrical conductivity value. It also provides excellent fabrication properties and is machined especially in the heat treated condition where close machining tolerances can be held. It can also be welded, brazed and soldered by traditional methods as well as being resistance weldable.

Key features:

The mechanical properties of Colisbro are:

30mm dia

30< dia 50mm

50< dia 90mm

Ultimate Tensile Strength (N/mm²)

640

600

550

0.2% Proof Strength (N/mm²)

590

510

430

Elongation (%)

10

10

10