Iron-silicon alloy and alloy product, exhibiting improved resistance to hydrogen embrittlement and method of making the same

An iron-silicon alloy exhibiting improved resistance to hydrogen embrittlement and sulfide stress cracking in a hydrogen-charging medium, said alloy consisting essentially of:

• about 1.3% to 1.7% weight of Si;
• and
• substantially the rest comprising Fe and inevitable impurities;
• and
• wherein said alloy is characterized by a quasi stable Fe--Si--H system upon substantial exposure to the hydrogen-charging medium, in which said Fe is a donor clement with respect to Si and Si is an acceptor element with respect to Fe.

An alloy, based on an iron-silicon alloy, exhibiting improved resistance to hydrogen embrittlement and sulfide stress cracking in a hydrogen-charged medium wherein H acts as a catalyst in a quasi-stable Fe--Si--H system, said alloy comprising:

• about 1.3% to 1.7% weight of Si;
• up to about 0.25% weight of C;
• about 0.07 to 1.2% weight of V;
• about 0.09 to 0.16% weight of Al;
• about 0.07 to 0.11% weight of REM;
• about 0.06% to 0.90% weight of Mn;
• up to about 0.035% weight of S;
• up to about 0.035% weight of P;
• about 0.01% to about 0.03% weight of N;
• and
• substantially the rest being Fe and inevitable impurities.

A structural steel product characterized by improved resistance to hydrogen embrittlement and sulfide stress cracking in an intensive hydrogen-charging environment, formed substantially from an alloy consisting essentially of:

• about 1.3% to 1.7% weight of Si;
• up to about 0.25% weight of C;
• at least one alloying element individually present and selected from the group consisting of Be, Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, W, Mo, Zn, Ge, Se, Rb, Zr, Nb, Ru, Ag, Cd, La, Cc, Pr, Nd, Gd, Tb, Dy, Er, Re, Os, Pb, Bi, U, N and other REM;
• and
• substantially the rest being Fe and inevitable impurities;
• and
• wherein H from said hydrogen-charging environment acts as a catalyst in a quasi-stable Fe--Si--H system.

An alloy, based on an iron-silicon alloy exhibiting improved resistance to hydrogen embrittlement and sulfide stress cracking in a hydrogen-charging environment, said alloy being substantially exposed to the hydrogen charging environment, said alloy consisting essentially of:

• about 1.3% to 1.7% weight of Si, wherein said Si interacts with Fe and H to form a quasi-stable Fe--Si--H system in which said Si is an acceptor element with respect to Fe, Fe is a donor element with respect to Si, and H is a catalyst;
• about 0.10% to 0.25% weight of C;
• at least one Fe--Si noninteractive alloying element, said Fe--Si noninteractive alloying element being characterized by an atom structure configured such that said alloying element is not a donor element or an acceptor element with respect to Fe or Si in said Fe--Si--H system;
• and
• substantially the rest comprising Fe and inevitable impurities.

A method of formulating the constituents of an alloy, based on an iron-silicon alloy, that exhibits improved resistance to hydrogen embrittlement and sulfide stress cracking in a hydrogen-charging medium, said method comprising the steps of:

• selecting Si in a concentration of between about 1.3% and 1.7% by weight;
• selecting at least one alloying element having an atom structure configured such that the alloy is adapted to form a quasi-stable Fe--Si--H system in the hydrogen-charging medium, whereby Fe is a donor element with respect to Si and Si is an acceptor element with respect to Fe and the alloying element is noninteractive with respect to Fe and Si;
• and
• providing Fe and inevitable impurities as the remaining constituents of the alloy.

A method of formulating the constituents of an alloy, based on an iron-silicon alloy, that exhibits improved resistance to hydrogen embrittlement and sulfide stress cracking in a hydrogen-charging environment, said method comprising the steps of:

• selecting Si in a concentration between about 1.4% to 1.6% by weight;
• selecting C in a concentration of up to about 0.26% by weight;
• selecting one or more alloying elements from the group consisting of:
• Be, Mg, Al, Cu, Sc, Ti, V, Cr, Mn, Co, Ni, Zn, W, Mo and REM, each of the alloying elements being selected such that the alloy is adapted to form a quasi-stable Fe--Si--H system in the hydrogen-charging medium, wherein Fe is a donor element with respect to Si and Si is an acceptor element with respect to Fe, and each of the alloying elements is Fe--S noninteractive with respect to Fe or Si in the system;
• and
• providing for Fe and inevitable impurities as the remaining constituents of the alloy.