Hot Isostatic Pressing Treatment of Diffusion Welds in SUS 304 Stainless Steel

Abstract

To eliminate all voids on diffusion-welded interface, diffusion-welded joints were treated using a hot isostatic pressing equipment without the canning of joints. The material used was SUS304 stainless steel. Results obtained are summarized as follows:
1. All voids on diffusion-welded interface, that are shut from the external environment and have not residual gas, are eliminated by the hot isostatic pressing treatment.
2. In the case of the welding surface prepared by a lathe, all voids on diffusion-welded joint are shut from the external environment when welded area ratio is above 35%.
3. It is difficult to eliminate voids in diffusion-welded joint made under the welding environment of Ar.
4. All voids of diffusion-welded joints are eliminated under hot isostatic pressing conditions of 1100°C, 2h and above 50 MPa.
5. The joints subjected to hot isostaic pressing treatment after diffusion welding have very small change in specimen shape, and the mechanical properties of the joints is not influenced by the roughness of welding surface.