It pointed out that the inner capillary crack was structure of segregated band which is formed of (Mn?Fe)S,loose pinholes and α-Fe, and is inherent in the tube billet.

Effect of electric current pulse on shrinkage cavity and porosity in casting ZA27 alloy;

Factor Analysis and Countermeasures of Porosity and Pipe in Ingot;

In this paper, analysis on the fissuring accident of ZGMn13Cr2Mo antifriction tup is performed, and the reason is believed to lie in serious casting defects of shrinkage cavity, porosity and inclusion.

Results indicate that the primary cause to the rupture of the screw in the process of torque force test is proved to be heavily existence of holes and pore gaps in the screw arising from the central looseness of the original billet.

Mechanism of central parosity and looseness of small billet is described and analysed.

The experimental results show that there are some internal metallurgy flaws such as looseness,shrink hole in the raw material of the axle,and bad widmanstatten structure from the overheating and over-burning during the heating of forging,the comprehensive effects of these factors cause the steel toughness to reduce,and the internal cleavage exists d.

A new heterogeneous polymerization process, in which water acted as a dispersed phase and methyl methacrylate (MMA) as a continuous phase, was developed to prepare porous poly(methyl methacrylate) (PMMA) resin.

Mold-filling, solidification and prediction of shrinkage porosity in Ti-46%Al alloy investment were performed using the ViewCast code, and the defects observed in the actual products agree well with the simulated results.

Vibroflotation compaction is a comparably mature method for the improvement of cohesiveless soils,but it is seldom used to strengthen loose silty fine sands,especially for depth over 15m.

They are as following: there is loose defect on the inner side,at the same time ther.