【作者】 张彦睿；

【导师】 张朝晖；

【作者基本信息】 西安建筑科技大学 ， 钢铁冶金， 2007， 硕士

【摘要】 HRB500热轧带肋钢筋强度高，韧性好，具有良好的抗震性能。达到相同强度的钢筋用量分别比HRB335、HRB400节省28％、14％，因此，将节约大量矿石、焦炭、水力、电力等资源，并减少环境污染。国外已淘汰335Mpa级以下的钢筋，广泛使用的是400Mpa级钢筋，而我国建筑用钢仍以HRB335钢筋为主。VN微合金化可以使钢筋性能达到GB1499-1998对HRB500MPaⅣ级钢筋的质量要求。研究并优化HRB500钢筋的生产工艺，对国民经济的发展具有重大意义。在小转炉和全连轧的工艺条件下，通过化学成分与工艺的配合，成功的开发了HRB500热轧带肋钢筋，吨钢综合成本可降616元。本文对钒元素、氮元素在钢中的作用及存在形式作了分析；对VN合金的强化机理进行了研究；探讨了化学成分、金相组织、冶炼工艺、轧钢工艺、对HRB500热轧带肋钢筋的影响；通过回归分析，得到了主要化学成分对HRB500钢筋抗拉强度与屈服强度的回归方程；并结合现场生产条件，提出了合适的工艺路线。试验结果表明：VN合金吨钢加入量为1.1Kg时，钢中V、N的平均含量达到0.08％、0.0096％，钢筋的平均屈服强度和抗拉强度分别达到546Mpa，701Mpa，平均延伸率为20％，强屈比1.28，冷弯、反弯及焊接性能完全满足国标要求。用VN合金微合金化后钢筋屈服强度增量在150Mpa以上，钢中增氮后充分发挥了钒的沉淀强化作用。VN合金是生产HRB500热轧带肋钢筋最为有效的、低成本的微合金化方式。更多还原

【Abstract】 HRB500 hot-rolled ribbed steel bar has the characters of high strength, good toughness and good shock resistance. To achieve the same strength, the dosage of steel bars will save a lot (28% to HRB335, 14% to HRB400). HRB500 steel bar is a kind of high efficiency material, a large number of ore, coke, water, and electricity will be retrenched if HRB335 steel bars is replaced. Also, environment will be benefited from using HRB500. Nowadays, the steel bars of 400Mpa were widely used instead of 335Mpa overseas. Well, the opposite situation to china, where HRB335 were mainly used in the construction of architecture. VN micro alloyed steel can satisfy the standard of GB1499-1998 on the mechanical property of HRB500. To research and develop the production process of HRB500 is of great significance to the national economy.In the process of small converter and tandem rolling, the HRB500 were successfully developed with VN alloy.The cost of the steel bars reduced 616RMB per ton.The effect and existence shape of vanadium& nitrogen were analyzed in this paper, the influence of chemical composition, micro-structure, the way of smelting and rolling to HRB500 were discussed. Then, the regression equation of main chemical composition (containingC, Mn, V) to the mechanical property was figured out by regression analysis. In the end, the production processes of HRB500 were given.The experimental results show that: the average content of vanadium& nitrogen is 0.08%, 0.0096% by adding VN alloys 1.1 Kg per ton. The average yield strength and tensile strength reaches 546Mpa and 701Mpa. The specific elongation is 20%, σ_b/σ_s equals 1.28. The performance of cold bending and reverse bending are up to grade. All the figures above were higher than the national standard. The yield strength increases 200Mpa by VN alloy. The effect of precipitation hardening of vanadium was engendered by nitrogen. It is proved that VN alloy is the efficient way of micro alloying.更多还原