Figure 5
The panels compare 17-4 P H and H-13 specimens across successive examination stages. Panel a shows the fracture area optical view of the 17-4 P H specimen with an irregular fractured surface and two prominent cavities, and panel b shows the H-13 fracture area optical view with a rough fractured surface and a central elongated cavity. Panel c shows the prepared 17-4 P H section for microscopic and S E M analysis with increased magnification, and panel d shows the corresponding H-13 section. Panel e shows the external 17-4 P H specimen area at 50 times magnification with a cellular microstructure, and panel f shows the external H-13 specimen area at 50 times magnification with scattered pores and a linear row of rounded defects. Panel g shows the external 17-4 P H specimen area at 200 times magnification with large polygonal grains, and panel h shows the external H-13 specimen area at 200 times magnification with a fine lath like microstructure and scattered pores. Panel i shows the internal 17-4 P H specimen area at 200 times magnification with finer polygonal grains, and panel j shows the internal H-13 specimen area at 200 times magnification with a similar lath like microstructure and isolated pores. Panel k shows the external 17-4 P H specimen area at 500 times magnification with enlarged polygonal grains, and panel l shows the external H-13 specimen area at 500 times magnification with numerous rounded pores distributed throughout the matrix. Panel m shows the internal 17-4 P H specimen area at 500 times magnification with polygonal grains and small pores, and panel n shows the internal H-13 specimen area at 500 times magnification with a lath like matrix containing rounded pores and larger voids. Scale bars indicate 1 millimetre in panels a through d, 200 micrometres in panels e and f, 50 micrometres in panels g through j, and 20 micrometres in panels k through n.(a–n) Optical, microscopic and SEM pictures of 17-4PH versus H-13 specimen sections
Source(s): Author’s own work