利用雷诺兹指数（Ryznar）对所研究的模拟地热水溶液的类型做出判断。通过在20号碳钢上进行化学镀得到镀层均匀的镀镍磷钢，并采用体式显微镜、全浸均匀腐蚀试验、电化学试验研究了镀镍磷钢、304不锈钢和20号碳钢三种常用金属管材在模拟地热水中的腐蚀结垢性能。结果表明：镀镍磷钢在模拟地热水中浸泡后所得表面垢层分散且量少，而304不锈钢表面生成的污垢较厚且集中，20号碳钢表面则生成了大量腐蚀与结垢产物。此外，镀镍磷钢和304不锈钢在全浸试验后未发生宏观腐蚀，但通过电化学试验进一步比较，镀镍磷钢的自腐蚀电流密度小于304不锈钢的，且其阻抗值明显大于304不锈钢的。因此,与304不锈钢和20号碳钢相比，镀镍磷钢具有更优良的耐蚀阻垢性能。

Ryznar index was used to judge the type of the simulated geothermal water. Uniform Ni-P eletroless coating was prepared on 20 steel surface via eletroless plating. Stereomicroscope, immersion test and electrochemical methods were used to study the corrosion and scaling properties of Ni-P electroless coating steel, 304 stainless steel and 20 carbon steel in simulated geothermal water. The results showed that the scales on the surface of Ni-P electroless coating steel were little and dispersed, but those of 304 stainless steel were thick and concentrated. 20 carbon steel showed many scaling and corrosion products. In addition, Ni-P electroless coating steel and 304 stainless steel were not corroded after immersing in simulated geothermal water, but the former had better corrosion resistance in terms of electrochemical tests, because the Ni-P electroless coating steel had smaller corrosion current density and larger impedance value. So the Ni-P electroless coating steel has better anti-scaling and corrosion resistance performance rather than 304 stainless steel and 20 carbon steel.