aluminum alloy hull meaning in Chinese

铝合金船体

X - ray inspection and quality classification for welded butt joints on aluminum alloy hull
铝合金船体对接接头x射线照相及质量分级
The aluminum alloy hull is empty inside to increase the intensity and dimension for heat transpiring , and to decrease the waste of eddy . the protection grade is 1p54
2铝合金外壳特殊中空结构，增大散热面积和强度，并形成隔磁，减少蜗流损耗，防护等级为1p54 。