Research On Thermal Fatigue Resistant Liner Alloy For Coke Pot

The lining board is an essential part of CDQ (Coke Dry Quenching) coke pot. The liner is easy to fail in the form of oxidation, cracking in atrocious working conditions as it works at about 1000 ℃ and bears the frequently wear and impact of hot coke. Therefore, the liner material must have good oxidation resistance, mechanical properties and creep properties at high temperature. Two kinds of austenitic heat resistant steel that used for new durable liner alloy were developed based on micro alloying principles in this paper.Mo, V, N were used as alloying elements to optimize the Fe-Cr-Ni-Mn heat resistant alloy. The orthogonal experiments showed that Mo could improve the hardness and high temperature oxidation resistance and V, N were benefit to the alloy properties too. The optimal alloy was Fe-0.3% C-20%Cr-4% Ni-4% Mn-2% Mo-1.5% Si-0.33% N-0.15% V and its air-cooled structure was composed of austenite and a little carbides.Six kinds of austenitic heat resistant alloy containing A1 were designed and the effect of A1 content on properties of heat resistant steel was analysed. Fe-0.1% C-14% Cr-20%Ni-2% Mn-2% Mo-3.5% A1-0.7% Nb-0.15% Si-0.01% B was chosen. The results showed that, Al2O3 and AlNi3 compounds formed at high temperature. And the compounds greatly improved the high temperature oxidation resistance and the thermal fatigue properties of the alloy.The results showed that the new alloys can be used as substitute liner material.