我厂生产的化肥高压容器,原采用大锻件、大螺栓紧固密封,但这种方式既费工又费料,不符合多快好省建设社会主义的原则。74年起陆续改用自紧式密封装置,其中C形环卡箍选用35铸钢(图1),第一批粗车后,发现表面有很多缺陷。经参考有关单位标准规定,初步订出了一个粗车后进行超声波探伤的参考标准: 1.不容许存在任何明显裂纹; 2.在弟功毫米区间不容许有)币2毫米当t直径的气孔、夹渣和砂眼等缺陷存在(图2); 图1.图2 3.其余各区允许有中(4毫米当盆的直径、距离>60毫米的单个分散的 I plant the fertilizer pressure vessel, the original use of large forgings, large bolt fastening seal, but this method is both laborious and wastes the material, does not meet the principle of building a socialist economy. Seventy-four since the switch to self-tight seal, which C-ring clamp selection of 35 cast steel (Figure 1), the first batch of rough car and found that the surface has many shortcomings. With reference to the relevant provisions of the relevant units, initially set out a reference standard after the rough car ultrasonic flaw detection: 1 does not allow any obvious cracks; 2 in the brother of the millimeter range does not allow) 2mm coin when t diameter pores (Fig. 2); Fig. 1. Fig. 2 3. The rest of the zones are allowed to have a middle (4 mm diameter when the pots are separated by a single dispersion of> 60 mm in diameter