【作者】 岳丽杰；

【导师】 徐成海； 王龙妹；

【作者基本信息】 东北大学 ， 流体机械及工程， 2006， 博士

【摘要】 本课题属于“十五”国家科技攻关计划“稀土应用工程”重大项目下的“稀土钢新工艺新品种关键技术及产业化研究”课题的一部分，课题编号为2002BA315A05。 随着国民经济建设的发展，铁道车辆用钢、集装箱板、建筑塔架等除了要求钢材有良好的耐腐蚀性能外，还同时要求有高的强度和韧性，对于综合性能的提高稀土能起关键作用。以Cu、P为基的基础上，利用我国丰富的稀土资源优势发展稀土耐候钢是适合我国基本国情的，同时满足了新一代高强耐大气腐蚀钢的要求。但是由于稀土在耐候钢中作用机理认识的不清楚，稀土耐候钢耐蚀机理和腐蚀产物的组成研究尚不完全，对于稀土提高钢的耐蚀性也只有一般性认识。从而导致在加入稀土工艺上及应用上存在很大程度上的盲目性，阻碍了稀土耐候钢的应用和新钢种的开发。随着现代冶金新技术新工艺的发展，钢的洁净度逐渐提高，稀土在日益洁净的钢中的作用机制也势必发生变化。为了更好地把具有中国资源特色的Cu-P-RE系耐候钢发扬广大，同时根据市场的需求不断开发新型稀土耐候钢，深入开展稀土在耐候钢中的作用及其机理、稀土加入工艺优化研究是首要的和必须的。 本文以洁净的10PCuRE钢为出发点，深入系统地开展了稀土在钢中的应用研究，包括稀土对耐候钢中非金属夹杂物、组织、机械性能、耐腐蚀性能等多方面的影响及其作用机理。 对于氧硫水平不同的试验耐候钢样和上海宝钢冶炼的现场耐候钢样，采用金相光学显微镜、图像分析仪、扫描电镜、电子探针等手段分析研究了稀土对不同洁净度的耐候钢中夹杂物的影响。得到了低氧硫组(O：～0.0020wt％，S：～0.0040wt％)稀土耐候钢，稀土含量在0.0065～0.01wt％的范围内，中氧硫组(O：0.004～0.007wt％，S：～0.008wt％)的稀土耐候钢，稀土含量在0.012～0.023wt％的范围内，长条硫化锰夹杂完全消失，钢中夹杂物基本上全部变性为细小弥散分布的球状稀土氧硫化物，85％以上的夹杂物尺寸小于2μm，从而稀土改变了钢中原有夹杂物的种类、形态、尺寸和分布，减少其对钢材性能的危害作用，甚至如此细小夹杂可以变为对钢材性能有利的因素，使得钢的组织细化，并且有一定的固溶稀土含量，从而提高了钢的综合机械性能，即改善材料的塑韧性的同时也提高了强度。两组试验Cu-P系耐候钢加入稀土后，提高了钢的横向冲击韧性，尤其对低温冲击值提高明显，促使钢从解理断裂向韧窝断裂转变。通过细化晶粒，稀土更多还原

【Abstract】 The subject is a part of " The industrial research and key technology of new process and new variety of RE steel " belonged to " Application project of rare earth " which is national "Shiwu" tackling key problem project. The subject number is 2002BA315A05.With the development of national economy construct, rail truck、 container and building tower request the steel material to have high strength and toughness except for excellent corrosion resistance. Rare earth can play a key role in increasing the comprehensive function of low alloy steel. It is adapt to our country situation developing RE weathering steel which makes use of the rich rare earth resource in our country. It satisfies the request of new generation high strength and atmosphere corrosion resistance steel at the same time. But the mechanism of action of rare earth in weathering steel is not clear, the study of corrosion resistance mechanism and corrosion products of RE weathering steel is still incomplete, it also only have the general understanding that rare earth can raise corrosion resistance of steel. The conditions make the addition craft and application of rare earth become very blind. The application of RE weathering and the development of new type of steel are restricted. Along with development of the new craft and technique of modern metallurgy, the cleanness of the steel is gradually raised. The mechanism of action of rare earth in the increasingly clean steel certainly will vary. For better developing the Cu- P- RE weathering steel that has the Chinese resources feature, exploiting the new RE weathering steel continuously according to the need of the market at the same time, It is initial and necessary that carrying on the deep study of action and mechanism of rare earth in weathering steel and the optimization study of RE addition craft.This artical takes the clean 10PCuRE steel as the study object, thorough systematically carries on the application study of rare earth in the steel, including various influence of rare earth on nonmetallic inclusion、 organization、 mechanical property and corrosion resistance更多还原