C-Mn-Ti系Q355B钢板的试制

TRIAL PRODUCTION OF C-Mn-Ti SERIES Q355B STEEL PLATE

低合金高强钢因其应用环境以及使用条件的特殊性,常常需要具有良好的力学性能。微合金化结合一定的热处理工艺,可以有效提高低合金高强钢的性能。研究钛微合金化及热处理工艺对低合金高强钢组织和性能的影响规律及作用机理,对提高材料的性能、扩大材料的应用具有重要的意义。以C-Mn-Ti系Q355B板坯的试制过程为例,研究了钛微合金化冶金成分及轧制工艺控制对材料显微组织和力学性能的影响规律;对比了4种不同轧制工艺条件下所生产钢板的力学性能和金相微观组织;并分析了材料的强化机制。0℃和20℃时Q355B板的低温冲击性能、屈服强度和冷弯性能分析结果表明,冶炼过程中形成的较大尺寸的TiN和链状的Ti 4C 2S 2对钢板的塑性和韧性均有负面影响;Ti微合金化后的钢板晶粒度均在9级以上;精开轧温度低于890℃,终冷温度在660±20℃波动时,钢板的综合力学性能最好。

Low alloy high strength steel often needs to have good mechanical properties due to its application environment and special use conditions.Microalloying combined with a certain heat treatment process can effectively improve the performance of low-alloy high-strength steel.The study of the influence law and mechanism of titanium microalloying and heat treatment process on the microstructure and properties of low-alloy high-strength steel is of great significance to improve the performance of materials and expand the application of materials.Taking the trial production process of C-Mn-Ti series Q355B slab as an example,the influence of metallurgical composition and rolling process control on the microstructure and mechanical properties of materials was studied.The mechanical properties and metallographic microstructure of steel plates produced under four different rolling process conditions were compared.The strengthening mechanism of the material was analyzed.The analysis results of low temperature impact performance,yield strength and cold bending performance of Q355B plate at 0℃and 20℃showed that the larger size of TiN and chain Ti 4C 2S 2 formed during the smelting process had a negative impact on the plasticity and toughness of the steel plate.The grain size of Ti microalloyed steel plates was above grade 9;when the precision rolling temperature is lower than 890℃and the final cooling temperature fluctuates at 660±20℃,the comprehensive mechanical properties of the steel plate are the best.