Boiling Boiling is the ordinary carbon steel structural steel hot rolled steel sheet. Boiling steel is a steel deoxidation incomplete, with only a certain amount of weak deoxidizer for molten steel deoxidation, higher oxygen content of molten steel, when molten steel into ingot molds, carbon and oxygen reaction produces a lot of gas, causing boiling liquid steel , boiling steel, hence its name. Low boiling steel carbon content, because they are not ferrosilicon oxygen, silicon steel is also low (Si <0.07%). Boiling steel outer layer is at boiling molten steel caused by churning crystallization conditions, so the surface clean, compact, good surface quality, good ductility and stamping properties, no major focus shrinkage, cut head less finished product rate, and boiling steel production process is simple, less ferroalloy consumption, low cost of steel. Boiling steel is used extensively for the manufacture of various stamping parts, construction and engineering structures and some of the less important parts of the machine structure. But boiling steel core portion of impurities, segregation is more serious, the organization is not dense, uneven mechanical properties. And because more gas content in steel, so the low toughness, cold brittleness and aging sensitivity greater welding performance is also poor. It is not suitable for the manufacture of boiling steel to withstand impact loads, welded construction work at low temperatures and other important structures.