Must first change the bars are the minimum technical requirements of the concept of varieties of steel, do not need to pay attention to change technology operations management ideas, modern production equipment has become continuously improve steel quality, an important condition for high-quality steel for the construction industry.
　　
　　The steelmaking operation requires to do the following:
　　
　　(1) hot metal pre-desulfurization; (2) smelting, Executive Dephosphorization, carbon, nitrogen technical rules; (3) non-slag tapping; (4) ensure that the level of cleanliness of the steel internal controls; (5) implementation of ingredients fine-tuning and composition, the temperature uniformity of the refining process; (6) avoid secondary oxidation of the molten steel and resulfurization; (7) a rigorous process to ensure internal control components.
　　
　　Capability index (Cp) - Analysis the deviation and operation deviation increase 6 times the ratio of:
　　
　　CP = F/6σ experiment