Low-cost and high-strength oxidation-resistant iron-nickel based alloy and preparation method thereof

Abstract

The invention discloses a low-cost and high-strength oxidation-resistant iron-nickel based alloy and a preparation method thereof. The alloy is high in strength, has good high-temperature steam oxidation resistance at 650-700 DEG C, and is low in production cost and obvious in cost performance advantage. The alloy comprises the following chemical components of: C, Cr, Fe, Co, Mo, W, Al, Si, Ti andNi; and the content of the components is as follows: the content of C is smaller than 0.08% and greater than 0, the content of Cr is smaller than or equal to 18% and greater than or equal to 14%, thecontent of Fe is smaller than or equal to 48% and greater than or equal to 37%, the content of Al and Si is smaller than or equal to 3.0% and greater than or equal to 0.5%, the content of Ti is smaller than or equal to 2.2% and greater than or equal to 2%, the content of Co is smaller than or equal to 1.5%, the content of Mo and W is smaller than or equal to 1.5% and greater than or equal to 0.4%, and the balance is Ni. During steam oxidation of the alloy in a range of 650-700 DEG C, a compact oxide layer containing a chromium oxide / aluminum oxide double-layer structure is obtained through selective oxidation.

Description

technical field [0001] The invention relates to a high-iron-iron-nickel-based alloy, in particular to a low-cost, high-strength, anti-oxidation iron-nickel-based alloy and a preparation method thereof. Background technique [0002] In order to solve the rapidly increasing demand for electricity, the increasingly prominent energy shortage and environmental pollution problems, the future development trend of advanced coal-fired power generation technology is: in the mid-term development of 5-10 years, on the basis of the existing 600 ℃ units, through Adopt secondary reheating and increase the main steam temperature to increase the thermal efficiency by 2-3 percentage points; in the long-term development of 10-20 years, the 700°C unit will be put into demonstration operation, and its thermal efficiency will reach 52-55%. Since the nickel-based superalloy required for a 700-degree power plant requires high preparation technology, it is expensive, about 10 times the cost of auste...

AI Technical Summary

Problems solved by technology

These alloys are highly resistant to corrosion, but are difficult to machine, have poor weldability, and are expensive

In contrast, low-cost and easy-to-process Ni-Fe-based alloys such as GH2984 do not meet the corrosion resistance requirements even though they contain 19wt.% Cr

In addition, some elements are beneficial to improve the strength and mechanical properties of the alloy, but they are not good for the oxidation resistance of the alloy, and it is easy to cause the oxide film to peel off, etc.

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