In this paper, the corrosion behavior of 304 stainless steel was investigated in the tidal zone of South China Sea through the field exposure tests. Results reveal that specimens exposed for 0.5 years exhibit minimal corrosion, with surfaces predominantly covered by algae, calcium-magnesium deposits, and barnacle. With prolonged exposure, the number of barnacles attached increases and occluded corrosion micro-cells are formed on the attachment zone, aggravating the localized corrosion condition. Electrochemical results show that specimen exposed for 0.5 years has a self-corrosion potential of -0.07 V (vs. SCE), while that for two years shifts negatively to -0.15 V accompanying a self-corrosion current density increase from 1.91 × 10–8 A cm−2 to 3.89 × 10–8 A cm−2. With prolonged exposure, barnacle attachment increases progressively, reaching 30

This study investigates the aging behavior of carbon-fiber-reinforced brominated bisphenol-A epoxy vinyl ester resin (CFBPA), a marine-grade composite material, through long-term natural exposure testing in Qingdao’s marine atmosphere. Using a comprehensive analytical approach incorporating Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and tensile testing, we systematically characterized the evolution of the chemical, morphological, thermal, and mechanical properties of CFBPA under environmental stressors. The results demonstrated that UV radiation initiates significant resin matrix degradation, whereas prolonged exposure exacerbates carbon fiber deterioration, collectively impairing the mechanical performance of the composite. Microscopic analysis revealed that matrix delamination was predominantly initiated at the fiber–matrix interface. These findings provide critical insights for the development of enhanced environmental protection strategies for marine composite applications, particularly for optimizing interfacial bonding and UV-resistant formulations.

Natural exposure test was carried out on carbon fiber reinforced composites in the marine atmospheric environment of the South China Sea for 0.5 a, 1 a, 1.5 a and 2 a. Based on obtained mechanical properties such as tensile, bending and shear strength of the carbon fiber reinforced composite after exposure test, the grey relational analysis method was adopted, and the environmental damage factor Rr was proposed to comprehensively characterize its mechanical property. According to the value of Rr, the grey prediction model GM (1,1) and the natural weathering model with radiation as independent variable were established respectively. The results show that resin matrix degradation thinning, fiber exposure and other aging phenomena occurred under the influence of irradiation and humidity-heat in the marine atmospheric environment of the South China Sea. Micro-crack damage were found on its surface after 2 years of exposure, and its comprehensive mechanical properties (Rr) decreased with aging time. The accuracy of the grey prediction model reached level 1 (good), while the prediction error of the natural weathering model for the mechanical properties of the carbon fiber reinforced composite after exposure for different periods was less than 0.50

In order to meet the development needs of deep-sea oil and gas resources, deep-sea corrosion coupon tests were carried out in the South China Sea, the Western Pacific Ocean, and the Indian Ocean, which can provide a strong guarantee for the rationality of material selection of oil and gas pipelines, platforms and other facilities. In-depth studies were conducted on the environmental adaptability of typical carbon steel and low alloy steel materials after exposure for one year in the deep-sea environment of different sea areas. The main environmental factors affecting deep-sea corrosion behavior were also collected and analyzed. The results showed that the corrosion morphology of carbon steel and low alloy steel in deep sea environment was more uniform than that in the shallow seawater. With the increase of seawater depth, the evolution law of their corrosion rates in different sea areas was similar, with an obvious decline of corrosion rate in the beginning. The gray correlation results indicated that it was mainly controlled by temperature and dissolved oxygen. The high hydrostatic pressure had limited effect on accelerating the deep sea corrosion rate of carbon steel and low alloy steel, but it promoted the formation of more uniform corrosion morphology.

Abstract The corrosion problem of metal materials in the South China Sea is serious. In order to meet the needs of rapid construction and development of islands and reefs in the South China Sea, it is necessary to establish a rapid evaluation method for the environmental adaptability of materials, which can provide effective guidance for material selection and corrosion control in marine engineering design. According to the atmospheric environment characteristics of islands and reefs in the South China Sea, an accelerated corrosion environment spectrum was designed, and then the atmospheric corrosion behavior in the South China Sea and the indoor accelerated corrosion test environment was studied. The correlation between indoor and outdoor corrosion was verified based on grey correlation analysis, and the prediction model of atmospheric corrosion based on indoor accelerated test results was established. The results show that the corrosion morphology, corrosion type and corrosion kinetic laws of 0Cr18Ni9 stainless steel under the indoor and outdoor test conditions had high similarity. Also, their correlation degree reached 0.8052, further indicating a good correlation between indoor and outdoor corrosion. The established prediction model had a relatively high accuracy (Level 2), and its prediction error to outdoor corrosion result was less than 26.13%.

To evaluate the global seawater corrosivity and ensure the service safety of marine equipment, the methods of seawater corrosivity classification, which contained the standard metal corrosion rates method and the environmental factors evaluation method, are proposed and then applied to the seawater corrosivity classification in typical China seas. By comparing the results from both methods, the feasibility of the environmental factors evaluation method based on the grey relational model is verified. Furthermore, with the collection and processing of typical seawater factors data of global ocean, the corrosivity of global seawater is classified into six grades with the corrosion test data of carbon steel as baseline, and its distribution in different months is visualized by means of ArcGIS technology. The results show that the sea areas with high corrosivity are mainly located at equatorial and tropical sea areas, and for carbon steel, seawater temperature was the main influence on seawater corrosivity.

In order to evaluate the global seawater corrosivity and ensure the service safety of vessels, based on the combing and comparison of existing classification methods of seawater corrosivity, combining with the characteristics of data, the study of global seawater corrosivity was carried out by means of gray relational method, while the visualization of the corrosivity classification results was achieved combined with database and ArcGIS technology. The results show that the sea areas with high corrosivity are mainly located at equatorial tropics, and among a year, the corrosivity is higher in summer.

目的 实现高性能树脂基复合材料的环境适应性评价和使用寿命预测.方法 选取玻璃纤维增强不饱和聚酯(GF/197S)与玻璃纤维增强乙烯基脂(GF/905-2)2 种树脂基轻质复合材料,开展模拟海洋环境实验室盐雾、湿热和盐水浸泡环境9 600 h的加速老化试验.基于4种力学性能(拉伸强度、弯曲强度、压缩强度及层间剪切强度)开展材料老化行为规律研究,利用傅里叶变换衰减全反射红外光谱(ATR-FTIR)对树脂基体在 3 种加速老化环境中的分子链段与官能团变化情况进行分析,得到基体树脂的老化机理.利用外观、超声扫描成像、SEM分析树脂纤维界面的变化情况,明确树脂/纤维界面的失效模式.利用差示扫描量热分析(DSC)与热重分析(TG)分析 3种加速老化方式对玻璃纤维增强树脂复合材料(GFRPC)的玻璃化转变温度(tg)与热质量损失的影响.结果 3种老化方式对树脂基体的老化影响顺序依次为70℃/95%RH湿热、35℃盐雾、常温盐水浸泡.结论 得到了先进轻质树脂基复合材料的模拟海洋环境老化行为、失效模式以及树脂基体的老化机理,为实现高性能树脂基复合材料的环境适应性评价和使用寿命预测奠定了基础.

The deep-sea field exposure experiment of 5A06 aluminum alloy was carried out successfully in the South China Sea with the sea depths of 1200 m, 2000 m, and 3000 m for one year. Corrosion morphologies show that pitting corrosion and crevice corrosion as the main corrosion types occur on the specimen surface, and that the crevice corrosion makes more contributions. The corrosion data results show that average corrosion rate, maximum pitting depth and corrosion area ratio reduce with the sea depth increasing and that the highest values are 13.8 μm a−1, 87.2 μm and 18.32% for 1200 m specimen. XPS results show that the oxygen content decreases with the sea depth increasing while the magnesium content increases. Comparing with 1200 m specimen, 2000 m and 3000 m specimens display higher ratios of Al2O3: Al(OH)3 and MgO: Mg(OH)2, which may be ascribed to the slightly higher oxygen concentration. Mott–Schottky results show that donor densities and acceptor densities are 1.14 × 1024 cm−3 and 9.16 × 1023 cm−3 for 1200 m, 2.82 × 1023 cm−3 and 2.10 × 1023 cm−3 for 1200 m, and 3.11 × 1023 cm−3 and 4.05 × 1023 cm−3 for 3000 m, respectively.

针对复合材料在自然环境老化因环境因素复杂导致预测困难的问题,选取复合材料基材聚乙烯为研究对象,在青岛海洋大气环境下开展了 3、6、9、12、15、18和24个月的自然暴晒试验,基于拉伸和弯曲力学性能演变数据,考虑环境因素的综合影响作用,分别建立了以辐射量为自变量的自然风化模型和以老化时间为自变量的多因素叠加模型.结果表明,聚乙烯在青岛海洋大气环境下,拉伸性能、弯曲性能等力学指标随老化时间和总辐照量均呈下降趋势,24个月暴晒能够造成其表面微裂纹损伤.自然风化模型预测对聚乙烯拉伸性能和弯曲性能预测误差小于11.20％,而多因素叠加模型则小于3.07％,预测精度更高.

目的 充分利用海洋腐蚀数据,深入分析数据规律.方法 在BP神经网络的基础上引入遗传算法,以克服神经网络模型固有缺陷,提高预测精度和训练速度.结果 对GA-BP人工神经网络进行了简要阐述,并以铜合金在海水中的腐蚀数据为例,应用GA-BP人工神经网络建立了海水腐蚀预测模型,对预测结果进行了评价.结论 预测结果表明,模型能满足设计要求,具有较好的泛化能力.

The serial-type deep-sea environmental test device was used to investigate the corrosion behaviour of 1060 aluminium exposed at real sea for 0.5 year and 2 years. Specimens were deployed at a depth of 1200, 2000 and 3000 m, respectively. A three-stage corrosion process was proposed after analysing the corrosion profile and the corrosion products of the specimens. The corrosion regularity was studied by employing the imaging processing technology and grey correlation analysis. The results show that the 1060 aluminium is prone to pitting and crevice corrosion. For the 0.5 year period test, the corrosion rate increases from 0.0114 to 0.0147 mm year(-1) when the sea water depth increases from 1200 to 3000 m. For the 2 year period test, the corrosion rate first decreases and then increases when the sea water depth increases from 1200 to 3000 m, and the maximum corrosion rate at 3000 m depth is 0.006 mm year(-1). Oxygen content and conductivity are the most important factors affecting the corrosion rate.

Through marine natural environment tests, the corrosion behavior of T2 and B30 Cu-Ni alloy at different seawater depths of the South China Sea was studied. The corrosion morphology and corrosion product properties were investigated using different techniques, including 3D optical microscope, scanning electron microscope (SEM), x-ray diffraction analyzer (XRD) and electrochemical impedance spectroscopy (EIS). Based on the environmental factor monitoring data and corrosion rate data, environmental factor influence mechanism on corrosion behavior was discussed The results indicated that the corrosion rate of T2 decreased with seawater depths increasing, while it was opposite for that of B30 Cu-Ni alloy. The evolution law of the corrosion rates of T2 at different seawater depths was mainly controlled by changes in seawater temperature and dissolved oxygen concentration. The effect of hydrostatic pressure was limited on T2 corrosion rate, but high hydrostatic pressure could promote Cl− penetrating into the corrosion product film, forming a uniform corrosion morphology for T2. For B30 Cu-Ni alloy, it was simultaneously affected by dissolved oxygen concentration and hydrostatic pressure, and the corrosion product film was rich in Ni and Fe elements.

目的 研究40Cr在海水环境中的自然腐蚀行为.方法 采用形貌分析、腐蚀质量损失分析、XRD分析等方法对40Cr在青岛、舟山、三亚海水全浸区的腐蚀行为进行研究.结果 40Cr在不同海域中的腐蚀均较为严重,青岛及三亚海域的试样表面被大量海生物附着,舟山海域的试样表面则以泥沙沉积为主.去掉腐蚀产物后试样的腐蚀形貌以坑蚀为主.在试验周期内,随着时间的延长,试样的腐蚀速率逐渐减小,在不同周期内均以三亚海域的为最高.在相同条件下与普通碳钢(Q235)相比,40Cr的腐蚀速率偏高.随着时间的延长,青岛、舟山试样点蚀深度逐渐增加,而三亚试样点蚀深度则先增加后减小,同周期下青岛海域试样的点蚀深度最小.不同海域及周期下40Cr的腐蚀产物以稳态α-FeOOH及Fe2O3为主.结论 40Cr在三个海域的腐蚀形貌均以坑蚀为主,试验周期内试样在三个海域的腐蚀速率随时间延长逐渐减小,同周期下三亚海域试样的腐蚀最为严重;40Cr中C含量较高,在相同条件下其腐蚀速率要高于普通碳钢;40Cr的腐蚀产物以稳态成分为主,是由于Cr元素含量较普通碳钢增加,加速了钢的腐蚀产物到热力学稳定状态的转化.

目的 研究严酷海洋大气环境下,玻璃纤维增强树脂基复合材料的腐蚀老化规律.方法 通过实海大气环境试验,分析了南海岛礁大气环境下,复合材料暴露不同周期后的腐蚀形貌特征以及力学性能变化规律,建立了腐蚀老化性能预测灰色模型GM(1,1),并与青岛、厦门和三亚等典型海洋大气环境进行对比研究.结果 随暴露时间的增长,南海岛礁大气环境下的复合材料发生严重的纤维裸露,其弯曲强度呈下降趋势,基于弯曲强度建立的灰色模型GM(1,1)精度达到1级;与其他典型海洋大气环境相比,随着纬度的降低,复合材料的弯曲强度呈下降趋势.结论 灰色模型GM(1,1)对复合材料在岛礁等严酷海洋大气环境下的腐蚀老化性能预测精度较高.影响复合材料性能的最主要环境因素为辐照,其次为相对湿度和温度.

目的 对比研究铜合金、紫铜在我国黄海、东海和南海海域具有代表性的港口海水环境中的污损、腐蚀行为.方法 依据GB 12763.6—2007《海洋调查规范》和GB/T 5776—2005《金属和合金的腐蚀试验方法》,通过实海挂片研究ZQMnD12-8-3-2、铜镍合金B10/B30和紫铜T2在我国典型海域青岛港口、舟山港口、三亚港口的生物污损与腐蚀状况.结果 铜镍合金B10、B30和紫铜T2在三海域均具有良好的抑制污损生物附着的性能,其中紫铜抑制污损生物附着的性能最为突出,但其腐蚀严重,腐蚀速率为3.97×10–2～8.48×10–2 mm/a;铸造青铜ZQMnD12-8-3-2虽然含铜量略高于铜镍合金B30,但由于其腐蚀产物易附着于材料表面,其污损抑制性能较差.结论 铜镍合金B10、B30和紫铜T2均有抑制污损生物附着的性能,但受不同海域环境因素和材料表面腐蚀产物致密性的影响有所差异.受泥沙水质影响,舟山港口内铜合金的腐蚀速率较高,腐蚀显著,三亚港口内紫铜的腐蚀速率最高.

目的 研究E420低合金钢材料在南海岛礁海水环境中的腐蚀行为规律.方法 通过外场暴露试验,分析E420钢在南海岛礁飞溅、潮差和全浸区带暴露0.5、1、1.5、2 a后的腐蚀形貌与动力学规律,并建立腐蚀速率灰色预测模型GM(1,1).结果 随暴露周期的延长,南海岛礁不同海水区带环境下,E420的腐蚀速率呈下降趋势,点蚀深度则整体达到一个较高的水平.飞溅区腐蚀速率数值最大,远大于一般海域,潮差次之,全浸最小.灰色模型GM(1,1)的腐蚀速率预测值与实测值相对误差低于25％.结论 南海岛礁不同海水区带E420腐蚀严重,以飞溅尤为严酷,锈层防护作用有限.腐蚀随时间倾向于不均匀发展.灰色模型GM(1,1)用于预测岛礁海水环境腐蚀可以取得较好的结果.

Pitting corrosion of 2Cr13 stainless steel was investigated by deep-sea exposure test at various depths of 500 m, 800 m and 1200 m in the South China Sea for 4 months. With the aid of electrochemical measurements in simulated deep-sea environments and grey relational analysis, the influence of deep-sea environments on passive film and the mechanism of pitting corrosion were discussed. The results indicated that with the increase of sea depth, pitting depth of 2Cr13 stainless steel increased, which can be attributed to the change of chemical composition and the degradation of pitting resistance of passive film. Film growth was greatly retarded in the condition of low seawater temperature and low dissolved oxygen content of deep sea, resulting in an unstable and vulnerable film. Pitting depth was most influenced by hydrostatic pressure, which can increase the adsorption and penetration of Cl− ion, and promote the proliferation of point defects in passive film, leading to rapid deconstruction of protective oxides of the film. Pitting sensitivity of 2Cr13 stainless steel increased eventually with the combination of accelerated dissolution and suppressed self-healing of passive film in deep sea.

Abstract In order to evaluate the seawater corrosivity of typical sea areas in China and provide guidance for the seawater corrosion protection on marine equipment and facilities, field exposure test was carried out. These typical sea areas under various climatic zones in China included Qingdao, Zhoushan, Sanya and a South China Sea reef, and Q235, copper, 5083 aluminum alloy and 304 stainless steel were chosen as test materials. The continuous monitoring of seawater environmental factors (temperature, salinity, pH, dissolved oxygen, etc.,) and the statistical work of first-year corrosion rates of test materials were done. Then, based on the metal corrosion rates method and the environmental factors method, the seawater corrosivity of these typical sea areas in China were classified, respectively. Furthermore, the classification results from the two methods were compared and analyzed.

目的 研究304和316L不锈钢在我国不同港口海水全浸区浸泡不同周期后的腐蚀规律.方法 进行港口海域实海全浸试验,利用三维视频拍摄、质量损失分析及图像处理等手段,对比分析不锈钢在青岛、舟山、三亚港口海水全浸区的腐蚀形貌、腐蚀速率、腐蚀深度和海生物附着面积.结果 两种不锈钢表面以点蚀和缝隙腐蚀为主,304不锈钢表面还产生严重的隧道腐蚀.不同港口海水中,304和316L不锈钢的腐蚀速率均较低,316L不锈钢的耐蚀性优于304不锈钢.三港口海域不锈钢表面形貌的差异明显,三亚试样表面海生物附着最多,舟山试样表面附着大量泥沙,三亚港口海域不锈钢的腐蚀速率小于舟山港口海域.结论 不同港口海水环境对不锈钢表面海生物种类及附着面积的影响显著,而不锈钢表面状态直接影响其腐蚀形貌.