What is the heat transfer performance and corrosion resistance of brass tubes?

What is the heat transfer performance and corrosion resistance effect of brass tube: The three elements of brass tube B, Sn and Ce are effective additions to improve the corrosion resistance of HAl77-2 aluminum brass. In terms of resistance to dezincing corrosion, the order of influence of each element is :B>Sn>Ce; In terms of seawater corrosion resistance, the order of influence degree of each element is Sn>B>Ce. Through the static corrosion test, electrochemical property test and corrosion morphology analysis of each group of samples in the orthogonal test, the results show that the corrosion rate of the alloy samples added 0.05%B, 0.5%Sn and 0.15%Ce in different solutions is the smallest, the corrosion surface is the most flat, the electrochemical corrosion property is the most stable, and the corrosion resistance is the strongest. The optimal test sample with 0.05%B, 0.5%Sn and 0.15%Ce added was compared with the theoretical optimal sample with 0.03%B, 1.50%Sn and 0.15%Ce. It was found that the corrosion performance of the optimal test sample was better than that of the theoretical optimal sample, indicating that the alloy with 0.05%B, 0.5%Sn and 0.15%Ce was added Aluminum brass tube is often used as heat exchange material in condenser because of its good processing performance, excellent corrosion resistance and good heat transfer performance of brass tube, but low-cost aluminum brass alloy pipe will have obvious dezincification corrosion tendency during use, so the corrosion resistance of aluminum brass alloy can be further improved The service life of long alloy pipe is of great practical significance. This experiment is based on HAl77-2 aluminum brass commonly used in industry, and adopts the design method of orthogonal test, static corrosion test and electrochemical test. HAl77-2 aluminum brass is a single phase α structure with Cu0.64Zn0.36 matrix, and the alloy with different contents of B, Sn and Ce elements does not change the phase composition of the alloy The three elements are solidly dissolved into the alloy matrix to produce solid solution strengthening effect, resulting in higher hardness values than the aluminum brass samples without other elements. The mechanical properties and corrosion resistance of HAl77-2 aluminum brass with different contents of B, Sn and Ce were determined by metallography (OM), scanning electron microscopy (SEM), temperature stretching and phase analysis (XRD). The corrosion resistance and mechanical properties of the optimal alloy with addition of 0.05%B, 0.5%Sn and 0.15%Ce are obviously different in different states. The order of corrosion resistance from strong to weak is: annealed state > recrystallized state > cast state > cold rolled state. The average dezincification layer thickness of brass tube is 332.2μm after 800℃×4h diffusion annealing. In terms of mechanical properties, the microstructure of recrystallized alloy samples is fine and uniform, and the mechanical properties are better than those of other alloy samples with different states.