Fatigue Strength Of Welded Joints After Pneumatic Shot Peening

Author:  Lunarski, J.
Source:  Conf Proc: ICSP-4, (p.273-280)
Doc ID:  1990033
Year of Publication:  1990
Abstract:  
The paper presents results of fatigue tests, performed on the welded joints, which have been strengthened by different methods and particularly by the pneumatic shot peening method, worked-out at Technical University of Rzeszow, Poland. Research was carried on the maraging N18K9M5T steel (R(m) = 1848 MPa; 51.5 RHN) and on the acid resistant 12H18N10T steel (Rm = 633 PMa; 205 BHN). Tests have been performed on the butt TIG-weldments by pure symetric rocking bending. The results of these tests indicate a possibility of increasing by circa 50% the fatigue strength limit of the 12H18N10T steel weldments as a results of treatment by pneumatic shot-peening. In case of N18K9M5T steel the fatigue limit in comparison with a weldment, strengthened by machining, increases additionally by 9 - 11% whereas in case of joints, not worked mechanically, even by 20 - 38%. Like for the uniform, not welded material, the results of treatment by pneumatic shot peening could be represented by a reliable mathematical model and that eases the process control and enables to forecast the fatigue characteristics of the pneumatically shot-peened parts. Descriptors: Weldments; Welded joints; Fatigue strength; Strengthening, Blast-burnishing; Pneumatic shot-peening; Surface layer