摘要 |
An iron based, fine-grained, martensitic stainless steel essentially free of delta ferrite has a nominal composition of (wt. %): 0.05<C<0.15; 7.5<Cr<15; 2<Ni<5; Co<4; Cu<1.2; Mn<5; Si<1; (Mo+W)<4; 0.01<Ti<0.75; 0.135<(1.17Ti+0.6Zr+0.31Ta+0.31Hf)<1; V<2; Nb<1; N<0.02; Al<0.2; Al and Si both present such that (Al+Si)>0.01; B<0.1; P<0.1; S<0.03; and the balance essentially iron and impurities. This steel is different from other martensitic stainless steels because thermal mechanical treatment is used to refine the grains and precipitate a relatively uniform dispersion of fine, coarsening-resistant, MX-type particles. The steel combines high strength and impact toughness with good corrosion resistance.
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