Institute Francais Du Petrole

Patrice Lefrancois

Xavier Longaygue

Martine Hourcade

The present invention relates to a method for predicting and controlling the hydrogen corrosion and embrittlement behavior of steels in the presence of H,S. In the method, at least the following stages are carried out: determining a characteristic value l,which is a function of the proportion of dislocations present in the lattice of a first steel sample treated under hardening conditions such that, after the hardening treatment, by quenching and tempering or by work hardening, the hardness of said steel reaches a maximum value at a threshold stress &sgr;,such that &sgr;,equals k&middot;R,k being less than or equal to Rp,of said steel; determining a characteristic value l,which is a function of the proportion of dislocations present in the lattice of a second treated steel sample; and comparing l,and l,, and if l,is less than or equal to l,, the treated steel of the second sample is said to be non sensitive to hydrogen corrosion and embrittlement in the presence of H,S according to the criterion defined by the value of k. When the resultant steel has a value l,less than l,, the resultant steel can be used for the armouring of wires, for example.

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Cormeilles en Parisis, France

Patrice Lefrancois