18MnMoNb钢是利用我国丰富的合金资源发展起来的一个钢种。屈服强度σ_s为50公斤力/毫米~2级。我厂生产的山东辛店电厂四号炉即由90毫米厚的该钢制成蒸发量为670吨/小时的汽包。汽包内径为1800毫米,经热加工后实际壁厚为84毫米,工作压力157公斤力/厘米~2。制成后,超声波探伤发现,在该汽包的电渣焊纵焊缝上,除了必须返修的裂缝外,尚有为数较多的“八” 18MnMoNb steel is the use of our abundant alloy resources developed a steel. The yield strength σ_s is 50 kgf / mm ~ 2. I plant in Shandong Xindian Power Plant No. 4 Furnace that is made of 90 mm thick steel drum evaporation of 670 tons / hour. Drum diameter of 1800 mm, the actual wall thickness after heat treatment of 84 mm, working pressure 157 kg force / cm ~ 2. Made after the ultrasonic flaw detection found that the steam drum in the ESR welds, in addition to the need to repair the cracks, there are still a large number of “eight”