2.4. Joint characterization
Optical microscopy was employed to characterize the weld. The
samples were etched with a solution containing 5 mL hydrochloric
acid, 5 mL nitric acid, and 5 mL acetic acid. Transverse tensile tests
were performed in accordance with GB/T 2651–2008 [14], Charpy Vnotch
impact tests were conducted in accordance with GB/T
2650–2008 [15], and bend tests were conducted in accordance with
GB/T 2653–2008 [16]. The specimen dimensions are presented in Fig. 3.
After the tensile test, the fracture morphology was observed with a
scanning electron microscope. Vickers hardness tests were carried out
on polished and etched specimens. The applied load was 10 kg. X-ray
nondestructive tests (NDTs) were conducted in accordance with GB/T
3323–2005 to examine the hot cracks in the weld [17].