The corrosion resistance of carbon steel to ethylene dichloride is considered "poor" (unsuitable under all conditions).* I would not recommend carbon steel as a material of construction for ethylene dichloride. With regard to pH, the greater the alkalinity, the slower the attack on carbon steel so keeping solutions basic should make them less corrosive. In neutral solutions, other factors such as aeration become more important so that corrosion behavior becomes difficult to predict.

* Davis, J.R. ed. Corrosion of Steels in Chemical Environments. ASM Specialty Handbook  - Carbon and Alloy Steels, ASM International: Materials Park, OH, 1996, p. 440.