鸟巢焊接工程
Bird’s nest welding project
十字形焊缝
cross-shaped welding seam
347L型不锈钢药芯焊丝
type 347L flux-cored wire for stainless steels
351型交直流方波氩弧焊机
351 alternating and direct square-waves argon arc welding machine
351 alternating and direct square-waves argon are
3E轴焊接构架式转向架
3E-axle welded frame type bogie