【作者】 张明锋；

【导师】 陈学东；

【作者基本信息】 浙江工业大学 ， 化工过程机械， 2008， 硕士

【摘要】 资料显示,近年来国内外发生多起形式类似的尿塔爆炸事件,造成了严重的人身伤害和物质损失。专家对于事故原因的分析存在一定的分歧,其一的解释是泄漏到层板间隙的检漏蒸汽中的碱性杂质浓缩后对层板产生严重应力腐蚀,进而造成塔体破裂。作为碱性溶液之一的碳酸盐环境应力腐蚀,已在化工炼油行业中的设备管道中被频繁报道,但是工业中的碳酸盐环境往往是由多种复杂介质构成的,认为由其引起的应力腐蚀开裂仅是定性的认识。由于我国压力容器常用钢在碱性环境方面的应力腐蚀定量数据积累甚少,故本文选择碱性环境之一的碳酸盐环境作为应力腐蚀试验溶液,进行试验研究,积累我国压力容器常用钢在该环境下的应力腐蚀定量数据,为设备管道的寿命预测奠定数据基础。本文选择几组碳酸盐溶液进行两种材料的慢应变拉伸试验以及在室温、90℃以及150℃三种温度和不同碳酸盐中进行16MnR和15MnVR钢的预裂纹试样（WOL）应力腐蚀试验。主要的结论如下:（1）慢拉伸试验表明在所选碳酸盐溶液中材料没有应力腐蚀倾向。（2）不同温度下,两种材料在Na₂CO₃溶液中的预裂纹试验未发生应力腐蚀开裂,试样表面存在致密的表面膜。（3）不同温度下,两种材料在NaHCO₃和混合溶液中未发生应力腐蚀开裂,试样表面存在较为严重的蚀孔,存在应力腐蚀的可能性。更多还原

【Abstract】 The material demonstrated that, sevaral similar accidental explosions of urea synthesizers occurred in recent years on the world, which had caused the serious human damage and material loss. The analysis of accidents’ cause had certain differences. The stress corrosion cracking（SCC） of alkalescence was one explanation,Which induced the outburst of vessel’s body, and then the accidental explosions happened. In the industry of chemical and oil refining ,the SCC in the carbonate solution were often reported on the equipment and pipelines,which is one of the alkalescence solution. But the SCC of carbonate in the industry circumstance was just a qualitative analysis,and the industry circumstance always contain complex mediums,not just the carbonate. Because really few quantitative data of the SCC of the own pressure vessel commonly used steel in alkalescence solution were accumulated, hence the carbonate solution is choosed as the testing solution,in which the Stress corrosion cracking（SCC） of 16MnR steel and 15MnVR steel were studied by the method of stress corrosion test for pro-cracked wedge-open loading（WOL） specimens and slow strain rate testing （SSRT）.The main research conclusions are as follows: 1 .SSRT indicated that the material has very low sensitivity of SCC in thechoosed carbonate solution.2.At different temperatures, the WOL specimens of two steel did not takeplace SCC in the Na₂CO₃ solution which were choosed in the testing, anddense film exists on the surface of specimens.3. At different temperatures, the WOL specimens of two steel did not takeplace SCC in the NaHCO₃ solution which were choosed in the testing,Corrosion pin holes exist on the surface of specimens,which could be thepossibility of SCC.更多还原