求翻译：先预热再保温焊接工艺。将Q345钢板进行焊前预热，预热完成后立即施焊，焊接完成后用保温棉进行保温是什么意思？

Preheated insulation welding process. Q345 steel plate preheated before, immediately after completion of warm welding, soldering is completed with cotton insulation insulation

Warm up and then keep warm soldering processes. Will Q 345 steel welded to the warm-up, and warm-up immediately after welding, soldering is completed with a warm cotton to keep warm

Preheating again keeps warm first the welding craft.Carries on front the Q345 steel plate welds preheating, after preheating completes executes immediately welds, after the welding completes carries on the heat preservation with the heat preservation cotton and kapok

Preheating before welding technology of thermal insulation. Q345 preheating before welding the steel, preheating is complete immediately after welding, welding after complete with insulation wool insulation

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