The material selection should be reconsidered. The carbon content is rather high for ease of welding. As already mentioned, low hydrogen practices, high preheat, high interpass temperature, and controlled cooling are a must.
To comply with AWS D1.1, the welding procedure must be qualified by testing. The materials in this case would have to be the same as that being welded in production. In short, the cast node would have to be used when the WPS is qualified.
I would be concerned about using any material coming out of China. At issue is the control of the chemistry of the cast steel nodes, specifically the carbon, sulfur, and phosphorus content. Some reputations are hard earned and there is ample reason to proceed with caution.
Best regards - Al