Alloys for hardbanding weld overlays
AssigneeScoperta, Inc.
InventorsJustin Lee Cheney, John Hamilton Madok
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Abstract
Disclosed herein are iron-based alloys having a microstructure comprising a fine-grained ferritic matrix and having a 60+ Rockwell C surface, wherein the ferritic matrix comprises <10 μm carbide precipitates. Also disclosed are methods of welding comprising forming a crack free hardbanding weld overlay coating with such an iron-based alloy. Also disclosed are families of alloys capable of forming crack-free weld overlays after multiple welding passes.
Claims20
An iron-based alloy having a microstructure comprising a fine-grained matrix, wherein the ferritic matrix comprises:
- Nb-carbide precipitates having sizes less than 10 μm;
- and
- hard precipitates having grain sizes less than 10 μm and comprising at least two of Mo, W, C, and B;
- wherein the alloy has a Rockwell C hardness greater than 50;
- and wherein the alloy comprises a combination of one or more of the following alloy chemistries, given in weight percent:
- Fe76.62Cr5.12Nb4.27V2.7C1.07B0.82W7.6Ti0.2Si0.5Mn1.1;
- Fe76.99Cr5.12Nb4.27V2.7C0.7B0.82W7.6Ti0.2Si0.5Mn1.1;
- Fe76.89Cr5.12Nb4.27V2.7C0.8B0.82W7.6Ti0.2Si0.5Mn1.1;
- Fe76.79Cr5.12Nb4.27V2.7C0.9B0.82W7.6Ti0.2Si0.5Mn1.1;
- Fe83.93Cr5Nb4.3V0.5C0.8B1.25W3T0.2Si0.52Mn0.5;
- Fe81.68Cr5Nb4.3V0.5C0.8B2.5W4Ti0.2Si0.52Mn0.5;
- Fe80.4Cr5Nb4.3V0.5C0.8B3W2Ti0.2Si0.65Mn1.15;
- Fe82.45Cr5Nb4.3V0.5C0.8B1.25Mo3Ti0.2Si2Mn0.5;
- Fe82.1Cr5Nb4V0.5C0.8B0.9Mo3.5Ti0.2Si2Mn1;
- Fe79.1Cr5Nb4V0.5C0.8B0.9Mo3.5Ti0.2Si5Mn1;
- Fe82.95Cr5Nb4.3V0.5C0.8B1.75Mo3Ti0.3Si0.4Mn1;
- Fe82.75Cr5Nb4.3V0.5C0.8B1.95Mo3Ti0.3Si0.4Mn1;
- Fe83.45Cr5Nb4.3V0.5C0.8B1.25Mo3Ti0.3Si0.4Mn1;
- Fe88Cr3Nb4.3V0.5C0.8B1Mo2Ti0.3Si0.4Mn1;
- Fe84Cr3Nb3V1.4C0.8B1.1W5Ti0.3Si0.4Mn1;
- Fe85.21Nb3.44V1.6C0.8B1.25W6Ti0.3Si0.4Mn1;
- Fe81.15Nb4B1C2W11.45Si0.15Ti0.25;
- Fe81.05Nb4B2C1.1W11.45Si0.15Ti0.25;
- Fe80.15Nb4V1B1C2W11.45Si0.15Ti0.25;
- Fe81.15Nb4V1B1C1W11.45Si0.15Ti0.25;
- and
- Fe82.05Nb4B1C1.1W11.45Si0.15Ti0.25.
An iron-based alloy processing a Rockwell C hardness greater than or equal to 55, capable of being welded in two layers onto a 4137 6⅝″ O.D. toll joint to achieve a total weld thickness of at least 8/32″ without cracking;
- wherein the iron-based alloy comprises:
- a balance of Fe;
- between 4-6 wt. % Cr;
- between 0.8-1.2 wt. % Mn;
- between 4-5 wt. % Nb;
- between 0-1 wt. % V;
- between 0.6-1.1 wt. % C;
- between 1.25-2.25 wt. % B;
- between 2-4 wt. % Mo;
- between 0.1-0.5 wt. % Ti;
- and
- between 0.4-0.75 wt. % Si.
A composition of matter comprising:
- a balance of Fe;
- between 4-6 wt. % Cr;
- between 0.8-1.2 wt. % Mn;
- between 4-5 wt. % Nb;
- between 0-1 wt. % V;
- between 0.6-1.1 wt. % C;
- between 1.25-2.25 wt. % B;
- between 2-4 wt. % Mo;
- between 0.1-0.5 wt. % Ti;
- and
- between 0.4-0.75 wt. % Si.
A composition of matter comprising a combination of one or more of the following alloy chemistries, given in weight percent:
- Fe88Cr3Nb4.3V0.5C0.8B1.25Mo2Ti0.3Si0.4Mn1;
- Fe84Cr3Nb3V1.4C0.8B1.1W5Ti0.3Si0.4Mn1;
- Fe85.21Nb3.44V1.6C0.8B1.25W6Ti0.3Si0.4Mn1;
- Fe81.15Nb4B1C2W11.45Si0.15Ti0.25;
- Fe81.05Nb4B2C1.1W11.45Si0.15Ti0.25;
- Fe80.15Nb4V1B1C2W11.45Si0.15Ti0.25;
- Fe81.15Nb4V1B1C1W11.45Si0.15Ti0.25;
- and
- Fe82.05Nb4B1C1.1W11.45Si0.15Ti0.25.
Dependencies are inferred from the claim text.