Why are stainless steels hard to roll?

Why are stainless steels hard to roll?

A wide range of products can be rolled: steels, copper and its alloys, and so on. Even when mild steel is involved, there are many grades, determined by their chemical composition and even by their purity. It is also necessary to consider both the initial mechanical characteristics of the product – that is to say, before the first pass – and the evolution of these characteristics during subsequent passes. The way the material is hot rolled also influences the material’s characteristics: what temperature prevailed, the cooling conditions, and so on. It is therefore quite difficult to know the characteristics of the product being rolled.

The mechanical properties of the product to be rolled are the main parameters used in calculating pass schedules and the tensions to be applied.

What information do you have to have?

1) the yield point

2) the tensile strength

3) the elongation

Before rolling and after 20%, 40%, 60% and 80% reduction.

The specific pressures are needed to roll different materials showing as the above chart:

From the above, we can see the pressure needed to roll stainless steel increases very fast from 20% to 80% reduction. Therefore, it is easy to understand why stainless steels are hard to roll.