Lean alloy design with Niobium

It is well established that niobium adds value to many steel products, through improving the properties of the material

and enhancing the performance of end products.

 

Driven by the need to become increasingly cost-competitive, niobium can add considerable value to structural steel grades up to 355 MPa. It enables the design of leaner alloys, reducing the cost of production and without requiring any changes to the steelmaking or rolling mill processes.

 

 

Comparable properties with

reduced costs

For structural flat products up to 355 MPa yield strength, a small amount of niobium can be added.

 

Just 0.01% niobium will meet the mechanical properties required, whilst providing the opportunity to reduce alloying costs by up to 30% depending on the price of the ferroalloys.

355MPa

How is this achieved?

Niobium enables the design of a ‘leaner’ alloy. Adding a small amount of niobium can partially replace the amount of manganese required

to meet 355MPa yield strength.

For every 100 ton of 355 MPa steel produced, the additions can be:

355MPa
355MPa
355MPa
355MPa

The specific example below shows the relative amounts of niobium and manganese required to meet 350 MPa yield strength.

355MPa
355MPa

How much can I save on my alloying costs?

For these types of structural flat steel products, Morosov et al demonstrated that there is a strong correlation between niobium and manganese content with respect to yield strength and tensile strength. As you can see from the following figures, varying the relative amounts of niobium and manganese enables the requirements for a specific yield strength and tensile strength to be met.

355MPa
355MPa
355MPa
355MPa

From this example, at a production level of 300,000 tons per year, you can see a saving of 28% on alloying costs, representing an actual saving of 2,036,807 USD per year.

355MPa

Finally, the niobium-based lean alloy design can also be applied to higher performing steels, those with greater yield strength than 355 MPa. We can use our rolling mill simulator ‘MicroSim’, to provide you with the optimum rolling mill process to meet your specifications for these higher performance steels.

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