A ferritic heat-resistant stainless steel resistant to high temperature oxidation and its manufacturing method

Abstract

The invention relates to a high temperature oxidation resistant ferrite heatproof stainless steel and a manufacturing method thereof. The high temperature oxidation resistant ferrite heatproof stainless steel comprises the following chemical components by weight percentage: less than or equal to 0.02% of C, less than or equal to 0.5% of Si, less than or equal to 0.5% of Mn, 17-20% of Cr, less than 0.02% of N, less than 0.02% of P, less than 0.02% of S, 0.1-0.2% of Ti, 0.3-0.6% of Nb, 0.3-0.8% of W, 0.05-0.13% of Re, greater than or equal to 0.9% and smaller than or equal to 1.3% of Nb+W-Re+Ti , greater than or equal to 4.5% and smaller than or equal to 7.5% of (Nb+W+Ti) / 10(C+N), and the balance Fe and inevitable impurities. The ferrite heatproof stainless steel provided by the invention does not contain Al and Co, reduces the casting technology difficulty, has a highest use temperature up to 1050DEG C, and under a high temperature of 1050DEG C, has high temperature mechanical properties (yield strength and tensile strength) and high temperature oxidation resistance superior to 022Cr18NbTi ferrite stainless steel and even superior to Cr20Ni12Si2 austenite heatproof stainless steel, but has a price only about half of that of Cr20Ni12Si2 austenite heatproof stainless steel.

Description

technical field [0001] The present invention relates to a ferritic stainless steel and its manufacturing method, in particular to a ferritic heat-resistant stainless steel resistant to high temperature oxidation and its manufacturing method. Exhaust system high temperature end components. Background technique [0002] Heat-resistant stainless steel is used in high-temperature service environments, such as thermal power generation, atomic energy, aerospace, aviation, petrochemical and automotive fields. Heat-resistant steel can be divided into austenitic heat-resistant steel, ferritic heat-resistant steel and duplex heat-resistant steel. Among them, austenitic heat-resistant steel has good high-temperature oxidation resistance, high-temperature strength, and good toughness, but the cost is relatively high; ferritic heat-resistant steel is low in cost and has a small thermal expansion coefficient, and is more and more favored by users. [0003] In the field of automobiles, t...

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Problems solved by technology

[0014] 1) For heat-resistant steel with low Cr content, the oxidation resistance is weak, and the general service temperature does not exceed 650°C;

[0015] 2) For heat-resistant steel with high Cr content, it contains a certain amount of Al or Co. Al requires high metallurgical technology in the casting process and is easy to form precipitates to block the nozzle. Adding Co will significantly increase the cost

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