海洋紧固件选择指南：沿海和海洋环境的材料、涂层和应用。
海洋环境挑战
海洋环境对紧固件的要求最严苛。盐水、湿度、紫外线辐射和波浪和风的机械应力共同加速腐蚀和机械故障。
海洋级材料
A4（316）不锈钢是海洋应用的标准，含16%铬、10%镍和2%钼。超双相不锈钢用于极端环境，钛用于需要强度和耐腐蚀性的关键应用。
海洋用保护涂层
热镀锌（HDG）用于大气海洋暴露，达克罗美具有良好的耐盐雾性能，环氧涂层具有优异的耐化学性和耐水性，不锈钢包层结合碳钢强度和不锈钢耐腐蚀性。
海洋应用
水上区域：热镀锌或达克罗涂覆碳钢足够。飞溅区：A4不锈钢最低。水中：A4不锈钢用于淡水浸没，超双相用于盐水。
安装注意事项
海洋紧固件安装需要额外注意：螺纹润滑、扭矩控制、避免异金属配合、预加载、定期检查、文档记录。
常见问题
See frequently asked questions below.
Why do stainless fasteners gall in marine environments?
Stainless steel is prone to galling (thread seizure) when installed without lubrication or with excessive torque. Always use marine-grade lubricant during installation.
Can I use galvanized fasteners underwater?
Not recommended. HDG works above water but rapidly degrades in saltwater immersion. Use A4 stainless or super duplex for underwater applications.
What's the difference between 304 and 316 stainless for marine use?
316 contains molybdenum which significantly improves chloride corrosion resistance. Use 304 only for protected indoor marine environments. Always use 316 for outdoor marine exposure.
How often should marine fasteners be inspected?
Annual inspection is minimum. More frequent inspection (6 months) for critical structures and harsh environments. Inspect for corrosion, loosening, and fatigue cracks.
Can I paint over stainless fasteners?
Not necessary and not recommended. Paint won't adhere well to stainless and may hide corrosion problems. Leave stainless fasteners unpainted.