螺杆压缩机阳转子轴断裂及预防措施

对输送放火炬气的LG-30/8型湿式水冷双螺杆压缩机阳转子轴断裂的原因进行了分析,通过分析腐蚀产物和观察断口形貌,判断为湿硫化氢环境下发生的腐蚀疲劳破坏,并存在有应力腐蚀开裂倾向。影响轴断裂的主要因素:介质成分复杂、腐蚀性强,压缩机转子处于化学腐蚀和应力腐蚀的环境;梳齿密封与轴的磨擦;变截面处应力集中倾向大;转子轴所承受交变应力;马氏体不锈钢对钝化膜破坏的自修复能力不足;热处理中组织相变不均匀等。对于2Cr13整体转子,采取改进热处理工艺、提高材料的机械性能、减小断裂处的应力集中和控制冷却水的腐蚀性等措施,可有效防止轴断裂。采取2Cr13螺杆与35Cr Mo(或25Cr2Mo VA等)轴组合的镶嵌结构转子,螺杆的耐腐蚀和轴的抗断裂性能皆较好,可用于新制转子和旧转子的修复。

Rupture of Male Rotor in Screw Compressor and Prevention Measures

The causes of rupture of male rotor in the LG - 30/8 wet water - cooling screw compressor for flare gas are studied. The analysis of corrosion products and observation of rupture＇s morphology conclude that the rupture is the corrosion fatigue failure under the environment of wet hydrogen sulfide, which is coupled with stress corrosion cracking. The main factors affecting the rotor rapture are： chemical corrosion and stress corrosion environments of compressor rotor due to complex compositions of corrosive media, attrition between seal and rotor, larger stress concentration at the cross section, alternating stress on the rotor, in - sufficient self - repair of austenitic for damages of passivation film and uniform structure phase transformation in heat treatment. For the Crl3 integrated rotor, the rupture of rotor can be prevented by improvement of heat treatment process, improvement of mechanical performances of materials, minimization of stress concentration at cracks and control of corrosivity of cooling water, etc. When the rotor with 2Cr13 screw rod and 35CrMo （ or 25Cr2MoVA） male rotor are selected, the crew rod and shaft offer good corrosion resistance and rupture resistance. They can be used in the new rotors and repair of old ones.