Abstract: A method for manufacturing a weldable steel component having a chemical composition including, by weight: 0.40%?C?0.45%; 0.75%?Si?1.50%; 0.3%?Mn?3%; 0%?Ni?5%; 1.11%?Cr?4%; 0%?Cu?1%; 0.410%?Mo?1.5%; 0.410%?Mo+W/2?1.5%; 0.038%?Nb?0.3%; 0.0005%?B?0.010%; 0.006%?N?0.025%; Al?0.9%; Si+Al?2.0%, optionally at least one element selected among V, Nb, Ta, S and Ca, in contents less than 0.3%, and among Ti and Zr in contents not more than 0.5%, the rest being iron and impurities resulting from the preparation, the aluminium, boron, titanium and nitrogen contents, expressed in thousandths of %, of said composition further satisfying the following relationship: B??×K+0.5, (1) with K=Min (I*; J*), I*=Max (0; 1), and J*=Max (0; J), I=Min(N; N?0.29(Ti?5)), J=Min(N; 0.5(N?0.52 Al+?{square root over ((N?0.52 Al)2+283)})), and whereof the structure is bainitic, martensitic or martensitic/bainitic and additionally comprises 3 to 20% of residual austenite.

Abstract: The invention concerns steel building components whereof the chemical composition comprises, by weight: 0.40 %=C=0.50%, 0.50%=Si=1.50%, 0%=Mn=3%, 0%=Ni=5%, 0%=Cr=4%, 0%=Cu=1%, 0%=Mo+W/2=1.5%, 0.0005%=B=0.010%, N=0.025 %, Al?0.9%, Si+Al=2.0%, optionally at least one element selected among V, Nb, Ta, S and Ca, in contents less than 0.3%, and among Ti and Zr in contents not more than 0.5%, the rest being iron and impurities resulting from the preparation, the aluminium, boron, titanium and nitrogen contents, expressed in thousandths of %, of said composition further satisfying the following relationship: B=?×K+0.5, (1) with K=Min (1*; J*), I*=Max (0;1) and J*=Max(0;J), I=Min(N; N?0.29(Ti?5)), J=Min {N; 0.5 (N?0.52 Al+v(N?0.52 Al)2+283)}, and whereof the structure is bainitic, martensitic or martensitic/bainitic and additionally comprises 3 to 20% of residual austenite. The invention also concerns a method for making said components.

Abstract: A method for manufacturing a weldable steel component having a chemical composition including, by weight: 0.40%?C?0.45%; 0.75%?Si?1.50%; 0.3%?Mn?3%; 0%?Ni?5%; 1.11%?Cr?4%; 0%?Cu?1%; 0.410%?Mo?1.5%; 0.410%?Mo+W/2?1.5%; 0.038%?Nb?0.3%; 0.0005%?B?0.010%; 0.006%?N?0.025%; Al?0.9%; Si+Al?2.0%, optionally at least one element selected among V, Nb, Ta, S and Ca, in contents less than 0.3%, and among Ti and Zr in contents not more than 0.5%, the rest being iron and impurities resulting from the preparation, the aluminium, boron, titanium and nitrogen contents, expressed in thousandths of %, of said composition further satisfying the following relationship: B??×K+0.5, (1) with K=Min (I*; J*), I*=Max (0; 1), and J*=Max (0; J), I=Min(N; N?0.29(Ti?5)), J=Min(N; 0.5(N?0.52 Al+?{square root over ((N?0.52 Al)2+283)})), and whereof the structure is bainitic, martensitic or martensitic/bainitic and additionally comprises 3 to 20% of residual austenite.

Abstract: The invention concerns a method for making an abrasion resistant steel plate having a chemical composition comprising: 0.35%?C?0.8%, 0%?Si?2%, 0%?Al?2%, 0.35%?Si+Al?2%, 0%?Mn?2.5%, 0%?Ni?5%, 0%?Cr?5%, 0%?Mo?0.50%, 0%?W?1.00%, 0.1%?Mo+W/2?0.50%, 0%?B?0.02%, 0%?Ti?2%, 0%?Zr?4%, 0.05%?Ti+Zr/2?2%, 0%?S?0.15%, N<0.03%; optionally from 0% to 1.5% of Cu; optionally Nb, Ta or V with Nb/2+Ta/4+V?0.5%; optionally less than 0.1% of Se, Te, Ca, Bi or Pb; the rest being iron and impurities; the composition satisfying: 0.1%?C*=C?Ti/4?Zr/8+7×N/8?0.55% and 1.05×Mn+0.54×Ni+0.50×Cr+0.3×(Mo+W/2)1/2+K>1.8, with K=0.5 if B?0.0005% and K=0 if B<0.0005% and Ti+Zr/2?7×N/2?0.05%; hardening after austenitization while cooling at a speed>0.5° C./s between a temperature>AC3 and ranging between T=800?270×C*?90×Mn?37×Ni?70×Cr?83×(Mo+W/2) and T?50° C.; then at a core speed Vr<115×ep?1.7 between T and 100° C., (ep=plate thickness in mm); cooling down to room temperature. The invention also concerns the resulting plate.

Abstract: The invention concerns a method for making an abrasion resistant steel plate having a chemical composition comprising: 0.1%?C<0.23%; 0%?Si?2%; 0%?Al?2%; 0.5%?Si+Al?2%; 0%?Mn?2.5%; 0%?Ni?5%; 0%?Cr?5%; 0%?Mo?1%; 0%?W?2%; 0.05%?Mo+W/2?1%; 0%?Cu?1.5%; 0%?B?0.02%; 0%?Ti?0.67%; 0%?Zr?1.34%; 0.05%<Ti+Zr/2?0.67%; 0%?S?0.15%; N<0.03%, optionally 0% to 1.5% of Cu; optionally Nb, Ta and V such that Nb/2+Ta/4+V?0.5%; optionally Se, Te, Ca, Bi, Pb contents ?0.1%; the rest being iron impurities. Additionally: 0.095%?C*=C?Ti/4?Zr/8+7×N/8, Ti+Zr/2?7×N/2?0.05% and 1.05×Mn+0.54×Ni+0.50×Cr+0.3×(Mo+W/2)1/2+K>1.8, with K=1 if B?0.0005% and K=0 if B<0.0005%. After austenitization, the method consists in: cooling at a speed >0.5° C./s between a temperature between AC3 and T=800?270×C*?90×Mn?37×Ni?70×Cr?83×(Mo+W/2) and about T?50° C.; then cooling at a speed 0.1<Vr<1150×ep?1.7 between T and 100° C., (ep=plate thickness in mm); cooling down to room temperature and optionally planishing.

Abstract: The invention concerns weldable steel building components whereof the chemical composition comprises, by weight: 0.10%?C?0.22%, 0.50%?Si?1.50%, AI?0.9%, 0%?Mn?3%, 0%?Ni?5%, 0%?Cr?4%, 0%?Cu?1%, 0%?Mo+W/2?1.5%, 0.0005%?B<0.010%, N?0.025%, optionally at least one element selected among V, Nb, Ta, S et Ca, in contents less than 0.3%, and/or among Ti and Zr in contents not more than 0.5%, the rest being iron and impurities resulting from preparation, the aluminium, boron, titanium and nitrogen contents, expressed in thousandths of %, of said composition further satisfying the following relationship: B??×K+0.5, (1) with K=Min (I*; J*), I*=Max (0; I) and J*=Max (0; J), I=Min (N; N?0.29(Ti?5)), J=Min {N; 0.5 (N 0.52 AI+?j(N 0.52 AI)2+283)}, the silicon and aluminium contents of the composition additionally verifying the following conditions: if C>0.145, then Si+AI<0.95 and whereof the structure is bainitic, martensitic or martensitic/bainitic and further comprises 3 to 20% of residual austenite.

Abstract: A method for producing a plate of steel which is resistant to abrasion and whose chemical composition includes, by weight: 0.24%?C<0.35%; 0%?Si?2%; 0%?Al?2%; 0.5%?Si+Al?2%; 0%?Mn?2.5% 0%?Ni?5%; 0%?Cr?<5% 0%?Mo?1%; 0%?W?2%; 0.1%?Mo+W/2?1%; 0%?B?0.02%; 0%?Ti?1.1%; 0%?Zr?2.2%; 0.35%<Ti+Zr/2?1.1%; 0%?S?0.15%; N<0.03%, optionally up to 1.5% of copper; optionally at least one element selected from Nb, Ta and V at contents such that Nb/2 +Ta/4+V?0.5%; optionally at least one element selected from among Se, Te, Ca, Bi, Pb at contents which are less than or equal to 0.1%; and the balance being iron and impurities resulting from the production operation. The chemical composition further complying with the following relationships: C*=C?Ti/4?Zr/8+7×N/8?0.095% and 1.05×Mn+0.54×Ni+0.50×Cr+0.3×(Mo+W/2)1/2+K>1.8 with: K=0.5 if B?0.0005% and K=0 if B<0.0005%.

Abstract: The invention concerns a method for making an abrasion-resistant steel part consisting of 0.1%?C?0.23%; 0%?Si?2%; 0%?AI?2%; 0.5%?Si+AI?2%; 0%?Mn?2.5%; 0%?Ni?5%; 0%?Cr?5%; 0%?Mo?1%; 0%?W?2%; 0.05%?Mo+W/2?1%; 0%?B?0.02%; 0%?Ti?0.67%; 0%?Zr?1.34%; 0.05%?Ti+Zr/2?0.67%; 0%?S?0.15%; N<0.030, optionally 0% to 1.5% of Cu; optionally Nb, Ta and V such that Nb/2+Ta/4+V?0.5 %; optionally Se, Te, Ca, Bi, Pb contents ?0.1%; the rest being iron and impurities. Additionally: 0.095%?C*=C?Ti/4?Zr/8+7×N/8, Ti+Zr/2?7×N/2?0.05% and 1.05×Mn+0.54×Ni+0.5O×Cr+0.3×(Mo++W1/2)1/2+K>1.8, with K=1 if B?0.0005% and K=0 if B<0.0005%. After austenitization, the method consists in: cooling at a speed >0.5° C./s between AC3 and T=800?270×C*?90×Mn?37×Ni?70×Cr?83×(Mo+W/2) and about T?50° C.; then cooling at a speed 0.1<Vr<150×ep?1.7 between T and 100° C., (ep=thickness of plate in mm); cooling down to room temperature and optionally planishing. The invention also concerns the resulting plate.

Abstract: The invention concerns a method for making an abrasion resistant steel plate having a chemical composition comprising: 0.35%?C?0.8%, 0%?Si?2%; 0%?AI?2%; 0.35%?Si+AI?2%; 0%?Mn?2.5%; 0%?Ni?5%; 0% ?Cr?5%; 0%?Mo?0.050; 0%?W?1%; 0,1%?Mo+W/2?0.5%; 0%?B?0.02%; 0%?Ti?2%; 0%?Zr?4%; 0.05%?Ti+Zr/2?2%; 0%?S?0.15%; N?0,03; optionally 0% to 1.5% of Cu; optionally Nb, Ta or V with Nb/2+Ta/4 +V?0.5%; optionally less than 0.1% of Se, Te, Ca, Bi or Pb; the rest being iron and impurities; the composition satisfying: 0.1 %<C*=C?Ti/4?Zr/8+7×N/8?0.55% and 1.05×Mn+0.54×Ni+0.5O×Cr+0.3×(Mo+W/2)1/2+K>1.8, with K=0.5 if B ?0.0005% and K=0 if B<0.0005% and Ti+Zr/2?7×N/2?0.05%; hardening after austenitization while cooling at a speed >0.5 ° C./s between a temperature >AC3 and ranging between T=800?270×C*?9O×Mn?37×Ni?70×Cr?83×(Mo+W/2) and T?50° C.; then at a core speed Vr<1150×ep?1.7 between T and 100° C., (ep=plate thickness in mm); cooling down to room temperature. The invention also concerns the resulting plate.

Abstract: The invention concerns a method for making an abrasion resistant steel plate having a chemical composition comprising: 0.35%?C?0.8%, 0%?Si?2%, 0%?Al?2%, 0.35%?Si+Al?2%, 0%?Mn?2.5%, 0%?Ni?5%, 0%?Cr?5%, 0%?Mo?0.50%, 0%?W?1.00%, 0.1%?Mo+W/2?0.50%, 0%?B?0.02%, 0%?Ti?2%, 0%?Zr?4%, 0.05%?Ti+Zr/2?2%, 0%?S?0.15%, N<0.03%; optionally from 0% to 1.5% of Cu; optionally Nb, Ta or V with Nb/2+Ta/4+V?0.5%; optionally less than 0.1% of Se, Te, Ca, Bi or Pb; the rest being iron and impurities; the composition satisfying: 0.1%?C*=C?Ti/4?Zr/8+7×N/8?0.55% and 1.05×Mn+0.54×Ni+0.50×Cr+0.3×(Mo+W/2)1/2+K>1.8, with K=0.5 if B?0.0005% and K=0 if B<0.0005% and Ti+Zr/2?7×N/2?0.05%; hardening after austenitization while cooling at a speed>0.5° C./s between a temperature>AC3 and ranging between T=800?270×C*?90×Mn?37×Ni?70×Cr?83×(Mo+W/2) and T?50° C.; then at a core speed Vr<115×ep?1.7 between T and 100° C., (ep=plate thickness in mm); cooling down to room temperature. The invention also concerns the resulting plate.

Abstract: The invention concerns a method for making an abrasion resistant steel plate having a chemical composition comprising: 0.1%?C<0.23%; 0%?Si?2%; 0%?Al?2%; 0.5%?Si+Al?2%; 0%?Mn?2.5%; 0%?Ni?5%; 0%?Cr?5%; 0%?Mo?1%; 0%?W?2%; 0.05%?Mo+W/2?1%; 0%?Cu?1.5%; 0%?B?0.02%; 0%?Ti?0.67%; 0%?Zr?1.34%; 0.05%<Ti+Zr/2?0.67%; 0%?S?0.15%; N<0.03%, optionally 0% to 1.5% of Cu; optionally Nb, Ta and V such that Nb/2+Ta/4+V?0.5%; optionally Se, Te, Ca, Bi, Pb contents ?0.1%; the rest being iron impurities. Additionally: 0.095%?C*=C?Ti/4?Zr/8+7×N/8, Ti+Zr/2?7×N/2?0.05% and 1.05×Mn+0.54×Ni+0.50×Cr+0.3×(Mo+W/2)1/2+K>1.8, with K=1 if B?0.0005% and K=0 if B<0.0005%. After austenitization, the method consists in: cooling at a speed >0.5° C./s between a temperature between AC3 and T=800?270×C*?90×Mn?37×Ni?70×Cr?83×(Mo+W/2) and about T?50° C.; then cooling at a speed 0.1<Vr<1150×ep?1.7 between T and 100° C., (ep=plate thickness in mm); cooling down to room temperature and optionally planishing.

Abstract: The invention concerns a method for making an abrasion resistant steel plate having a chemical composition comprising: 0.35%?C?0.8%, 0%?Si?2%, 0%?Al?2%, 0.35%?Si+Al?2%, 0%?Mn?2.5%, 0%?Ni?5%, 0%?Cr?5%, 0%?Mo?0.50%, 0%?W?1.00%, 0.1%?Mo+W/2?0.50%, 0%?B?0.02%, 0%?Ti?2%, 0%?Zr?4%, 0.05%?Ti+Zr/2?2%, 0%?S?0.15%, N?0.03%; optionally from 0% to 1.5% of Cu; optionally Nb, Ta or V with Nb/2+Ta/4+V?0.5%; optionally less than 0.1% of Se, Te, Ca, Bi or Pb; the rest being iron and impurities; the composition satisfying: 0.1%?C*=C?Ti/4?Zr/8+7×N/8?0.55% and 1.05×Mn+0.54×Ni+0.5O×Cr+0.3×(Mo+W/2)1/2+K>1.8, with K=0.5 if B?0.0005% and K=0 if B<0.0005% and Ti+Zr/2?7×N/2?0.05%; hardening after austenitization while cooling at a speed >0.5° C/s between a temperature >AC3 and ranging between T=800?270×C*?90×Mn?37×Ni?70×Cr?83×(Mo+W/2) and T-50° C.; then at a core speed Vr<115×ep?1.7 between T and 100° C., (ep=plate thickness in mm); cooling down to room temperature. The invention also concerns the resulting plate.

Abstract: The invention concerns weldable steel building components whereof the chemical composition comprises, by weight: 0.10%?C?0.22%, 0.50%?Si?1.50%, AI?0.9%, 0%?Mn?3%, 0%?Ni?5%, 0%?Cr?4%, 0%?Cu?1%, 0%?Mo+W/2?1.5%, 0.0005%?B<0.010%, N?0.025%, optionally at least one element selected among V, Nb, Ta, S et Ca, in contents less than 0.3%, and/or among Ti and Zr in contents not more than 0.5%, the rest being iron and impurities resulting from preparation, the aluminium, boron, titanium and nitrogen contents, expressed in thousandths of %, of said composition further satisfying the following relationship: B?1/3×K+0.5, (1) with K=Min (I*; J*), I*=Max (0; I) and J*=Max (0; J), I=Min (N; N-0.29(Ti-5)), J=Min {N; 0.5 (N 0.52 AI+?j(N 0.52 AI)2+283)}, the silicon and aluminium contents of the composition additionally verifying the following conditions: if C>0.145, then Si+AI<0.95 and whereof the structure is bainitic, martensitic or martensitic/bainitic and further comprises 3 to 20% of residual austenite.

Abstract: The invention concerns a method for making an abrasion resistant steel plate having a chemical composition comprising, by weight: 0.24%?C?0.35%; 0%—Si—2%; 0%—Al?2%; 0.5%?Si+Al?2%; 0%?Mn?2.5% 0%?Ni?5 %; 0%?Cr?<5% 0%?Mo?1%; 0%?W?2%; 0.1%?Mo+W/2?1%; 0%?B?0.02%; 0%?Ti?1.1%; 0%?Zr?2.2%; 0.35%?Ti+Zr/2?1.1%; 0%?S<0.15%; N<0,03%, optionally 0% to 1,5% of copper; optionally at least one element selected among Nb, Ta and V in contents such that Nb/2+Ta/4+V?0.5%; optionally at least one element selected among Te, Ca, Bi, Pb in contents not more than 0.1%; the rest being iron and impurities resulting from the preparation, moreover the chemical composition satisfying the following relationships: 0.095%?C*=C?Ti/4?Zr/8+7×N/8 and 1.05×Mn+0.54×Ni+0.50×Cr+0.3×(Mo+W/2)112+K>1.8, with K=0.5 if B?0.0005% and K=0 if B<0.0005%. The method consists in subjecting the plate to a hardening, in rolling heat or after austenitization in a furnace; cooling the plate at a cooling speed higher than 0.5° C.

Abstract: The invention concerns a method for making an abrasion-resistant steel part consisting of 0.1%?C?0.23%; 0%?Si?2%; 0%?AI?2%; 0.5%?Si+AI?2%; 0%?Mn?2.5%; 0%?Ni?5%; 0%?Cr?5%; 0%?Mo?1%; 0%?W?2%; 0.05%?Mo+W/2?1%; 0%?B?0.02%; 0%?Ti?0.67%; 0%?Zr?1.34%; 0.05%?Ti+Zr/2?0.67%; 0%?S?0.15%; N<0.030, optionally 0% to 1.5% of Cu; optionally Nb, Ta and V such that Nb/2+Ta/4+V?0.5 %; optionally Se, Te, Ca, Bi, Pb contents ?0.1%; the rest being iron and impurities. Additionally: 0.095%?C*=C?Ti/4?Zr/8+7×N/8, Ti+Zr/2?7×N/2?0.05% and 1.05×Mn+0.54×Ni+0.5O×Cr+0.3×(Mo++W1/2)1/2+K>1.8, with K=1 if B?0.0005% and K=0 if B<0.0005%. After austenitization, the method consists in: cooling at a speed >0.5° C./s between AC3 and T=800?270×C*?90×Mn?37×Ni?70×Cr?83×(Mo+W/2) and about T?50° C.; then cooling at a speed 0.1<Vr<150×ep?1.7 between T and 100° C., (ep=thickness of plate in mm); cooling down to room temperature and optionally planishing. The invention also concerns the resulting plate.

Abstract: The invention concerns a method for making an abrasion resistant steel plate having a chemical composition comprising: 0.35 %?C?08%, 0%?Si?2%; 0%?AI?2%; 0.35%<Si+AI?2%: 0%?Mn?25%; 0%?Ni?5%; 0%?Cr?5%; 0%?Mo?0.050; 0%?W?1%; 0.1%?Mo+W/2?0.5%; 0%?B?0.02%; 0%?Ti?2%; 0%?Zr?4 %; 0.05%?Ti+Zr/2?2%; 0%?S?0.15%; N?0.03; optionally 0% to 1.5% of Cu; optionally Nb, Ta or V with Nb/2+Ta/4+V?0.5%; optionally less than 0.1% of Se, Te, Ca, Bi or Pb; the rest being iron and impurities; the composition satisfying: 0.1%<C*=C?Ti/4?Zr/8+7×N/8?0.55% and 1.05×Mn+0.54×Ni+0.5O×Cr+0.3×(Mo+W/2)1+2+K>1.8, with K=0.5 if B?0.0005% and K=0 if B<0.0005% and Ti+Zr/2?7×N/2?0.05%; hardening after austenitization while cooling at a speed >0.5° C./s between a temperature >AC3 and ranging between T=800?270×C*?9O×Mn?37×Ni?70XCr?83×(Mo+W/2) and T-50° C; then at a core speed Vr<1150×ep-?1.7 between T and 100° C., (ep=plate thickness in mm); cooling down to room temperature. The invention also concerns the resulting plate.

Abstract: A block is produced by juxtaposition and joining of at least one plate made of tool steel and of at least one plate made from mild steel. The block is hot rolled and then it is cooled to a temperature below 200.degree. C. The rolled block is tempered at a temperature above 450.degree. C. after cooling. The clad sheet obtained includes a layer made of tool steel having a tempered martensitic structure and containing primary carbides and a fine dispersion of secondary carbides.

Abstract: A block is produced by juxtaposition and joining of at least one plate made of tool steel and of at least one plate made from mild steel. The block is hot rolled and then it is cooled to a temperature below 200.degree. C. The rolled block is tempered at a temperature above 450.degree. C. after cooling. The clad sheet obtained includes a layer made of tool steel having a tempered martensitic structure and containing primary carbides and a fine dispersion of secondary carbides.

Abstract: A steel composition useful for the manufacture of articles and components having high abrasion resistance.