Martensites in austenitic stainless steel welded explosively

The morphology of induced and a martensites and the concentration of a' martensite in austenitic stainless steel (j-phase) welded explosively have been investigated by means of X-ray difiractometer measurement and transmission electron microscopy, a' martensite is hardly detected in the region near a welded interface. With Increasing distance from the interface the volume percent of a' martensite increases to the greatest value (several %) and then decreases monotonically. Selected area electron diffraction patterns have revealed the existence of*crystals as well as a' crystals in a y matrix. Thin platelets are separated by thin y platelets, and these platelets compose a band. Many parallel bands are distributed in a y crystal and a' crystals are formed by -A and y-a' transformations both inside and outside the bands. In the a' crystals there are dislocations of high density but no deformation twins. © 1980 Oxford University Press. All rights reserved.