Travel Japan - Moscow by trains / ferries through China

Hello,

I'd like to enter China from South Korea, probably the port of Qingdao and take the train to Mongolia in Beijing. Is there a way to avoid the expensive visa for China when travelling without flights/airports?
For example if I leave China within 24h (arrival port in China , day later taking train to Mongolia?) Another possibility is to take the ferry from Tokyo - Shanghai and take the train from there if there is a free transit zone.