Steel rimmed steel sheet as the name suggests is made by boiling hot rolled steel plate made of ordinary carbon structural steel. Rimming steel deoxygenation is a complete steel, steel liquid oxygen content is higher, when molten steel after the injection mould, carbon oxygen reaction to produce large amounts of gas, resulting in liquid steel was named after boiling state. Rimming steel with low carbon content, and because no FeSi deoxidization, so steel containing silicon amount<0.07%. Boiling steel outer layer is crystallized in the boiling state, so the surface clean, compact, good surface quality, good processing performance. Rimming steel no large shrinkage hole, deoxidizer used less, low cost of steel. Rimming steel heart of impurities, with the serious segregation, mechanical heterogeneity, more gas in steel, low toughness, cold brittleness and aging sensitivity is larger, the welding performance is poor, so it does not apply to manufacturing under impact load, welding pieces of..