Figure 2e shows the microstructures of base metal for
the high titanium content steel (B steel), which is mainly
made up of the typical tempered bainite. When the welding
heat input is 30 kJcm-1, the microstructures of CGHAZ
are mainly made up of the lath bainite together with a small
amount of granular bainite, as shown in Fig. 2f; this kind of
microstructure insures that the CGHAZ of the high titanium
content steel has high hardness and toughness after
welding. When the welding heat input is 50 kJcm-1, the