Large residual stress and delayed crack would be
produced after assembly and welding of largediameter cutterhead, hence,
the scheme of improving the surfacing welding quality by controlling preheating
temperature is put forward. The selfprotecting flux
cored wire is used to weld the shield tool plate by material Q345R, and the
variations of surfacing welding structure and performance at the preheating
temperature of 50, 100, 150 and 200 ℃ are studied
respectively. The results show that after preheating by 100 ℃, the residual stress is the least, the impact toughness is the
best, the microhardness gradient variation is the least, and the comprehensive
mechanical property is the best. The conclusions obtained by the test are used
to guide the selection of preheating temperature for surfacing welding of the
cutterhead. It has been proved in practice that by selecting the appropriate
preheating temperature, the onetime pass rate of UT
flaw detection results after welding of the cutterhead reaches 100%, and good
results have been achieved in practical application.
WU Qilong
. Influence of Preheating Temperature on Surfacing Welding Microstructure and Properties of Shield Cutterhead[J]. Tunnel Construction, 2020
, 40(8)
: 1154
-1159
.
DOI: 10.3973/j.issn.2096-4498.2020.08.007
