P-RE复合超细组织耐候钢的理论与技术

深入研究了P、RE、晶粒细化和组织类型等因素对钢铁材料耐大气腐蚀性能的影响规律和作用原理。研究发现,P改善耐大气腐蚀性能显著,也可有效提高钢的强度,由较高的P含量所导致的钢铁材料的冷脆问题可通过晶粒细化或超细化控制而显著改善;RE可显著改善钢铁材料的耐大气腐蚀性能,其主要作用机理是：在钢中形成的RE化合物、RE/Fe金属间化合物和固溶稀土等在腐蚀薄液膜中水解,并在pH值较高的阴极沉淀,从而起到缓蚀作用;晶粒细化有益于提高钢铁材料的耐大气腐蚀性能。通过集成上述3项技术,开发了新型的P-RE复合合金化超细组织经济型耐候钢。所开发的新材料成本优势明显,强韧性高,耐大气腐蚀性能可接近Cor-ten B钢水平。

Theory and Technology of Ultrafine Grained Weathering Steel with P and RE Combined Addition

In this paper,the progress and conclusions of this program will be introduced.P and Rare-Earth elements are known to be low cost and be able to improve weathering properties of steel materials obviously.However,the cold brittleness due to high P made P bearing steel difficult to be commercialized.It was found that the bottleneck of high P steel could be broken through by grain refinement,especially ultra refinement.Meanwhile,the research results showed that the grain refinement and ultra refinement is beneficial to weathering properties,which suggested that ultra-fine grained steel with high P has a potential in developing low cost weathering steel.On the other hand,the mechanism of that RE improves weathering properties has been revealed.It was found that RE enhances weathering properties by RE compound hydrolyzing,and then deposition in high PH value cathode,as a result,retards corrosion going on.Based on these research results,a new ultrafine grained and P-RE combining added weathering steel with high strength and toughness,especially excellent anti-corrosion properties similar to Cor-ten B steel has been developed in lab.