The reinforcing ring has the advantages of simple structure, easy manufacture and wide application. However, there is a layer of static air gap between the reinforcing ring and the shell, and the heat transfer effect is poor, resulting in the difference between the two temperature difference and thermal expansion, which is easy to cause thermal stress. When the reinforcing ring is welded with the shell, the rigidity of the joint is enlarged, and the cooling contraction of the diagonal weld is greatly restrained. In particular, the high strength steel hardening, welding crack sensitive, more prone to cracking. Because the reinforcing ring and the shell or the connecting metal do not form a whole, the fatigue resistance is poor. Therefore, it is necessary to limit the use of the lap welding structure.
GB 150---1998 regulations, the use of reinforcement ring structure should be followed when strengthening:
The standard tensile strength of steel, the lower limit of 1 sigma value b = 540MPa;
2, the thickness of the reinforcement ring is less than or equal to 1.5 n;
3, nominal thickness of the shell is less than 38mm n.