After casting billet is ingot steel products. Mainly from the manufacturing process of billet can be divided into two kinds: die casting billet, slab and the die casting process has been basically eliminated. Mainly from the shape is divided into two kinds:
Slab: cross section width and height of the ratio of the larger, mainly used for rolling plate.
Billet: equal cross section width and height, or a huge difference, mainly used for rolling steel, wire rod. ,
Billet was rolled steel, after processing can be used for mechanical parts, forging parts, processing all kinds of steel, steel Q345B channel steel, wire rod is the role of the billet.
Steel billet is used in the production of semi-finished products, generally cannot be used directly for the society. Steel billets and steel are strictly divided into standard, cannot decide to whether the business enterprise of the final product, and according to unified standards to perform the whole society. Typically, billet and the steel is relatively easy to distinguish, but for some steel billet, and have the same specification and same steel purposes (such as rolling tube billet), whether can be used for other industries, whether through steel processing process, whether through a finished product rolling mill processing to distinguish. 
Rectangular billet continuous casting billet and mainly general carbon steel, low carbon low silicon cold-rolled material, high quality carbon structural steel, high strength low alloy steel, special steel, etc.
The production process
Steel billet is produced by the method of through three processes:
It is through the steelmaking system of continuous casting equipment, directly by the molten steel pouring into billet;
The second is the steelmaking system in the production of steel ingot casting billet through system of steel rolling rolling equipment or processing of steel semi-finished products; Three is the steelmaking system production of steel ingot by forging the semi-finished product processing equipment. 
4 market movements
1, high domestic crude steel production
Although the domestic steel market has been weak in these days, and steel mills deficit to win more less, but it does not seem to affect the enthusiasm of steel production. According to figures from the cisa: early April, the domestic key enterprises crude steel output of 1.6973 million tons, the national forecasts crude steel output of 2.1239 million tons a day. And mid-april although ten-day monthly crude steel output has dropped, but still at a higher level. According to statistics, in the middle of April crude steel output was 1.6891 million tons a day national key enterprises, the national forecasts crude steel output of 2.1158 million tons a day. So much of the production and demand downturn in stark contrast, this also is a drag on one of the important factors of billet prices downward.
2, the billet demand has no obvious improvement
Although has entered the traditional peak season demand, steel billet actual demand situation there is no improvement, even weak parts in March, the market for manufacturer of may is more pessimistic. Currently, tangshan market view, the billet rolling operating at less than 80%, and the rolling factory procurement cautious, inventory control in the low post. Weaker terminal market, steel billet, the rose slightly, weakened purchasing immediately; And the price, demand is also no substantive improvement.
3, tangshan billet falling inventories
It is understood that in April tang shan area each big rolls billet stock began to decline, as of April 28, tangshan billet inventory around 1.25 million tons, than high roughly halved. But there is also a manufacturer said: some resources is made after converted to traders, actually is much larger than the inventory statistics, and 1.25 million tons of steel billet inventory is about 2.5 times in the same period last year.
In addition, China industry insight into network analysts believe the macroeconomic situation is weaker, the negative news is more steel and iron and steel industry the credit crisis will be adverse to the billet market outlook. But considering the steel mills had been losing money in production, make steel billet has certain defensive; And a small long vacation before five billet prices fell back quickly, it is likely to holiday makers to pull up some bedding.
Range of thickness: 150-240 - mm + / - 5 mm width range: 880-1530 - mm + / - 20 mm
Length: 3700-10000 - mm + / - 500 - mm
Cross-sectional size: 64 * 64; 82 * 82; 98 * 98; 124 * 124; 120 * 150; 152 * 164; 152 * 170 mm
Length: 9000 mm
Section of tolerance: billet: 1.0 + / - 2.0-1.0 + / - 1.0 mm slab: width: + / - 2.0 mm thickness: + / - 3.0 mm
The length tolerance: + / - 200 mm
Section diagonal tolerance: 3.5-8.0 MM
Billet section size protrusions requirements: < 1242 mm, do not allow; > = 1242 mm, < = 2 mm 1242 mm, < = 3 mm
Beheading (shear) extension deformation: < 1242 mm billet: no control; The slab: < = 15 mm
Surface tilt: no more than billet section 0.1
Bending: every 1 m length is not more than 10 mm.