Stainless steel reducers under internal pressure

The bending moment caused by the area pressure difference between the big and small ends of the stainless steel reducer under internal pressure causes the relative opening of the large end and the relative contraction of the small end. Under internal pressure, the circumferential stresses on the inner surface of the A403 Bw Seamless Ss 321 Pipe Concentric Stainless Steel Reducer, the large end of the eccentric side and the middle and outer surface of the eccentric side are the largest. The above theoretical results are verified by finite element numerical analysis and experimental verification. The experimental results also show that the bending radius and the cross-section radius of the annular shell increase with little change in the wall thickness under internal pressure.

　　Diameter expanding of stainless steel reducer is formed by using a blank smaller than the diameter of large end of stainless steel reducer, and by using an internal punching die to expand the diameter along the inner diameter of the tube blank. The expanding process mainly solves the problem that it is not easy for the large diameter pipe to be formed by reducing. Sometimes, according to the need of material and product forming, the methods of expanding and reducing are combined.

　　The circumferential stress formula and meridional stress formula of concentric reducer are derived under internal pressure. Under the corresponding structural parameters, the formula of circumferential stress of different-diameter elbow can be transformed into the formula of circumferential stress of concentric, eccentric or stainless steel reducer. On this basis, the limit pressure formula of the reducer is derived. The whole process is formed by the radial compression of the billet and the drawing process of the branch.

　　The hot-pressing forming of stainless steel reducer is to flatten the billet larger than the diameter of the tee to the size of the diameter of the tee and open a hole in the part of the drawing stainless steel reducer; the billet is heated and put into the forming die, and the blank is loaded into the punching die of the drawing stainless steel reducer; under the action of pressure, the billet is radially compressed and the metal direction is in the process of radial compression. The different diameter pipe flows in a direction and forms a branch pipe under the stretching of the die.