Impact and corrosion resistance properties of hot rolled plate products are evidently dependant on the initial liquid steel metallurgy, and afterwards on rolling and heat treatment practices.

A systematic evaluation on more than 100 heats of duplex 4462 with PRE: 35 has been carried out in order to quantify the influence of the liquid steel variations on the characteristics of the final products, the other production operations – rolling + heat treatment – being kept as constant as possible.

The key characteristics of the plate products that have been checked are:

– The Charpy-V impact energy

– The general and localised corrosion behaviour:

The variable elements that have been taken into account from the liquid steel metallurgy are:

– The major alloys balance: Ni ,Cr, Mo, N,...

– The deoxydation practice: Si, Al, Ca,...

– The inclusion cleanliness: S, O,:

These variables have been checked both on heat samples and plate samples.

The compilation of these data versus the aimed characteristics has allowed to draw important conclusions on the influence (or not) of the different parameters of the liquid metallurgy upon the main properties of this duplex grade.