Metal material having good resistance to metal dusting

A metallic material having metal dusting resistance which comprises, in mass %, C:

• not more than 0.2%, Si:
• 0.01-4%, Mn:
• 0.05-2%, P:
• not more than 0.04%, S:
• not more than 0.015%, Cr:
• 10-35%, Ni:
• 30-78%, Al:
• not less than 0.005% but less than 4.5%, N:
• 0.005-0.2%, and one or both of Cu:
• 0.015-3% and Co:
• 0.015-3% and further comprises at least one of the (a) group elements specified below, with the balance substantially being Fe, and of which the fn1 value defined by the formula (1) given below is not less than 50:
• (a) Mo:
• 0.05-10%, Ta:
• 0.05-5%, W:
• 0.05-5%, Ti:
• 0.01-3%, V:
• 0.01-1%, Zr:
• 0.01-3%, Nb:
• 0.01-3% and Hf:
• 0.01-1%;
• fn1=40Si+Ni+5Al+40N+10(Cu+Co) (1),
• wherein, in the above formula (1), the symbols of the elements represent the contents, in mass %, of the elements in the metallic material.

A metallic material having metal dusting resistance which comprises, in mass %, C:

• not more than 0.2%, Si:
• 0.01-4%, Mn:
• 0.05-2%, P:
• not more than 0.04%, S:
• not more than 0.015%, Cr:
• 10-35%, Ni:
• 30-78%, Al:
• not less than 0.005% but less than 4.5%, N:
• 0.005-0.2%, and one or both of Cu:
• 0.015-3% and Co:
• 0.015-3% and further comprises at least one of the (a) group elements specified below, with the balance substantially being Fe, and of which the fn1 value defined by the formula (1) given below is not less than 50 and the fn2 value defined by the formula (2) given below is not less than 0.003:
• (a) Mo:
• 0.05-10%, Ta:
• 0.05-5%, W:
• 0.05-5%, Ti:
• 0.01-3%, V:
• 0.01-1%, Zr:
• 0.01-3%, Nb:
• 0.01-3% and Hf:
• 0.01-1%;
• fn1=40Si+Ni+5Al+40N+10(Cu+Co) (1);
• fn2=(Mo/192)+(Ta/181)+(W/368)+(Ti/48)+(V/51)+(Zr/92)+(Nb/93)+(Hf/179) (2),
• wherein, in the above formulas (1) and (2) , the symbols of the elements represent the contents, in mass %, of the elements in the metallic material.