Hastelloy 选型指南：C-276、C-22、B-3 怎么选
哈氏合金家族简介
Hastelloy 是Haynes International公司的注册商标，代表一系列以镍-钼-铬为基础的超级耐蚀合金，在苛刻化学环境中具有卓越的耐腐蚀性能。在家族中，C-276、C-22和B-3是过程工业设备中最常指定的三个牌号。
Hastelloy C-276（UNS N10276）——全能型选手
C-276 含有约15.5%钼、16%铬和4%钨。这种平衡的化学成分使其对氧化性和还原性酸均具有抵抗力，包括含氯化物、硫酸盐和氟化物的混合酸介质。
典型应用：烟气脱硫（FGD）洗涤塔、含混合氧化剂的化工反应器、纸浆漂白设备、废弃物焚烧处理装置。
Hastelloy C-22（UNS N06022）——卓越的抗氧化和抗点蚀性能
C-22 将铬含量提升至约22%，钼保持在13%左右。更高的铬含量显著提高了对氧化性氯化物溶液以及点蚀/缝隙腐蚀的抵抗力。
选用场景：工艺介质含强氧化剂如三氯化铁或氯化铜、持续暴露于海水或盐水、必须最小化局部腐蚀风险。
Hastelloy B-3（UNS N10675）——专为盐酸环境优化
B-3 含高达28.5%的钼，铬含量很低。专为在所有浓度和温度下抵抗盐酸腐蚀而设计，包括共沸沸点条件。
关键特性：耐盐酸性能超越所有其他镍合金、相比旧牌号B-2具有更优的热稳定性、由于铬含量低在氧化性环境中适用性有限。
常见介质中的腐蚀速率对比
| 试验介质 |
温度（°C） |
C-276（mm/年） |
C-22（mm/年） |
B-3（mm/年） |
| 20%盐酸，沸腾 |
110 |
0.25 |
0.50 |
0.05 |
| 10%硫酸，沸腾 |
102 |
0.30 |
0.20 |
0.15 |
| 5%硝酸，沸腾 |
102 |
0.15 |
0.08 |
2.50 |
| 3%NaCl + 1%HCl，充气，80°C |
80 |
0.10 |
0.05 |
0.80 |
| 50%磷酸，沸腾 |
130 |
0.20 |
0.12 |
0.10 |
选型逻辑
- C-276： 氧化-还原混合介质且无单一腐蚀物种占主导时的默认选择
- C-22： 氧化性氯化物、海水或氧化性酸是主要威胁时的升级选择
- B-3： 专为盐酸服役设计的专用牌号
与我们的腐蚀工程团队联系，获取针对具体工况的牌号推荐
Hastelloy Selection Guide: C-276 vs C-22 vs B-3
The Hastelloy Family
Hastelloy is a registered trademark of Haynes International for a family of nickel-molybdenum-chromium superalloys renowned for exceptional corrosion resistance in aggressive chemical environments. Within the family, C-276, C-22, and B-3 are the most frequently specified grades for process industry equipment.
Choosing the correct grade prevents costly premature failure and unplanned shutdowns.
Hastelloy C-276 (UNS N10276) — The Universal Performer
C-276 contains approximately 15.5% molybdenum, 16% chromium, and 4% tungsten. This balanced chemistry delivers resistance to both oxidizing and reducing acids, including mixed-acid streams containing chlorides, sulfates, and fluorides.
It excels in:
- Flue gas desulfurization (FGD) scrubbers
- Chemical process vessels with mixed oxidizers
- Pulp and paper bleach plants
- Waste treatment incinerators
Hastelloy C-22 (UNS N06022) — Superior Oxidation and Pitting Resistance
C-22 elevates chromium to roughly 22% while keeping molybdenum near 13%. The higher chromium content dramatically improves resistance to oxidizing chloride solutions and pitting/crevice corrosion.
Select C-22 when:
- The process contains strong oxidizing agents such as ferric or cupric chlorides
- Seawater or brine exposure is continuous
- The risk of localized corrosion must be minimized
- Equipment operates in the "danger zone" of chloride concentration and temperature
Hastelloy B-3 (UNS N10675) — Optimized for Hydrochloric Acid
B-3 contains up to 28.5% molybdenum with very low chromium. It is specifically engineered for resistance to hydrochloric acid at all concentrations and temperatures, including the azeotropic boiling point.
Key characteristics:
- Exceptional HCl resistance superior to all other nickel alloys
- Improved thermal stability compared to legacy B-2 grade
- Lower susceptibility to Ni₄Mo precipitation during fabrication
- Limited utility in oxidizing environments due to low chromium
Corrosion Rate Comparison in Common Media
| Test Environment |
Temperature (°C) |
C-276 (mm/y) |
C-22 (mm/y) |
B-3 (mm/y) |
| 20% HCl, boiling |
110 |
0.25 |
0.50 |
0.05 |
| 10% H₂SO₄, boiling |
102 |
0.30 |
0.20 |
0.15 |
| 5% HNO₃, boiling |
102 |
0.15 |
0.08 |
2.50 |
| 3% NaCl + 1% HCl, aerated, 80°C |
80 |
0.10 |
0.05 |
0.80 |
| 50% H₃PO₄, boiling |
130 |
0.20 |
0.12 |
0.10 |
Data represent typical laboratory immersion test results. Actual service rates depend on velocity, aeration, and impurity levels.
Selection Logic
- C-276: Default choice for mixed oxidizing-reducing process streams where no single corrosive species dominates. Broadest applicability.
- C-22: Upgrade when oxidizing chlorides, seawater, or oxidizing acids are the primary threat. Best pitting resistance in the family.
- B-3: Specialist grade for hydrochloric acid service. Do not specify if oxidizing agents or dissolved oxygen are present.
Fabrication Considerations
All three grades are readily formed and welded. C-22 and C-276 develop sigma-phase risk if held between 650°C and 900°C for extended periods; rapid cooling after welding or hot forming is recommended. B-3 is more forgiving thermally but requires careful control of sulfur contamination during welding.
Field Note: In multi-stage chemical plants, upstream and downstream vessels may require different grades. Conducting a total lifecycle cost analysis often reveals that specifying the correct grade for each stage is cheaper than using one universal grade everywhere.
Talk to our corrosion engineering team for environment-specific grade recommendations at ay-alloy.com