某厂用HHH4-13型锅炉的上、下汽包各一个(汽包前筒身材料为20g,中、后筒身材料为 H11),改装成蒸发量为7吨/时的沸腾炉。 1975年6月投产至1979年7月,上汽包两次发生裂纹。第一次(见图 1)发生在1976年6月,汽包中筒靠炉前侧距前筒与中筒环缝765毫米,以汽包中心线上内弧长200毫米处 A plant HHH4-13 type boiler with the upper and lower drum each one (drum material before the drum body is 20g, middle and back body material H11), converted into evaporation of 7 tons / hour boiling furnace. Commissioned in June 1975 to 1979 July, SAIC cracked twice. The first time (see Figure 1) occurred in June 1976, the drum in front of the furnace tube away from the front cylinder and the cylinder ring seam 765 mm, the center line of the drum on the arc length of 200 mm