According to visual examination, chemical analysis,metallographic examination,mechanical inspection,scanning electron microscope examination and facture mechanics analysis of the failed N80(1) oil casing,the main reason for the failure of pipe is the combination of bad metallic phase,non-homogeneous chemical constitution and poor impact ductility.

Non quenched and tempered N80 oil casings of high quality have been produced on existing 180 production line at Baotou Iron and Steel(Group) Co.

When the K55 grade oil casing lathed thread,the thread flawed.

Apply CAE to the optimum design of petroleum casing pipe;

In view of the trial-production of J55 hot-rolled coiled sheet for petroleum casing pipe,rolling process control and comprehensive quality of the products were analyzed.

The technical characteristics and technological flow of grade N80 non-quenching & tempering casing steel produced by Tianjin Iron & Steel Co.

It also points out the problems existing in pipe hot rolling and in the scope of the production of round billet continuous casting, heat treatment and casing production and the solving methods.

Arc continuous cast billets are adopted to produce N80-1casing which has low eligible rate because of big flaws on the surface and small cracks inside.

Analyse residual stress of oil casing pipe in the sizing process by the FEM;

Study on multi focusing probes based on measuring wall thickness of oil casing pipe

In order to eliminate the size and roundness tolerance after the rolling and heat treatment of oil casing pipe,the straightening process should be used.

Technological practice of oil casing steel 39Mn2V with 150 t EAF-LF/VD-CC route;