Peak regulation in thermal power plants is an inevitable trend under the development of new energy.Under this condition

the initial condensing zone of steam turbine moves forward and the corrosion of low pressure cylinder intensifies.Several methods such as electrochemical testing

sample weight loss and metal surface topography analysis(SEM

EDS

XRD

and so on) were used to study the pitting corrosion characteristics of 2Cr13 steel(the material of low pressure cylinder of the steam turbine) under the conditions of simulated initial setting zone

with different mass concentrations and different mass concentration ratios of Cl~- to SO_4~(2-) of three anions(Cl~-

SO_4~(2-) and CH_3COO~-).The test results showed that

the corrosion rate of 2Cr13 steel increased with the anions’mass concentration

and the maximum corrosion rate(0.095 23 g/(m~2·h)) occurred when was 2:1.Pitting corrosion was observed in all samples

and the number of pitting corrosion increased with the anions’mass concentration.With the change of

Cl~-and SO_4~(2-) on the metal surface of 2Cr13 steel changed from site competitive adsorption effect to mutual synergistic effect

resulting in the intensification of uniform corrosion and pitting corrosion.The chloride ions and sulfate in the initial coagulation zone of steam turbine will accelerate the corrosion rate of 2Cr13 steel and the occurrence of point corrosion.In actual operation of power plant

measures should be taken to prevent the leakage of condenser tubes and the broken particles of positive resin should be effectively removed.