In the situation of smelting strict control, we should figure out the delamination defects before producing. And we should know that this would lead to the plasticity and toughness trouble for us. How to solve it? Improving the cleanliness of the steel would be one of the option. In order to solve this, to reduce osteoporosis center segregation and center on the need to increase the proportion of equiaxed slab. Under this situation, series problems would be here for our manufacturers to solve. Meeting technical standards would be our final goal to guarantee high quality steel pipe for our customers.