高性能厚规格正火桥梁钢Q370qE-Z35的生产开发

Production and Development of High Performance Thick Gauge Normalized Bridge Steel Q370qE-Z35

通过加入Nb、Ti、Cu等元素进行微合金强化,配合TMCP轧制工艺,开发了正火Q370qE-Z35桥梁钢,结合显微组织观察及力学试验研究了正火温度对组织及性能的影响。结果表明,正火后金相组织为珠光体和铁素体,且正火温度为860、870及880℃时,沿板厚1/4处的组织晶粒度依次达到9、10、7.5级。随着正火温度的升高,强度及韧性不断下降,在860℃时强韧性匹配最佳,且同时具备低屈强比及高Z向性能。综合性能完全满足标准要求,富裕量较大。

The normalized Q370qE-Z35 bridge steel was developed by adding Nb,Ti,Cu and other elements for microalloying and TMCP rolling process.The effects of normalizing temperature on microstructure and properties were studied by microscopic observation and mechanical tests.The results show that the microstructure after normalizing is pearlite and ferrite,and the normalized temperature is 860,870 and 880℃,the grain size along the plate thickness of 1/4 reaches 9,10,7.5 level.As the normalizing temperature increases,the strength and toughness decrease continuously,and the toughness matching is best at 860℃,and at the same time,it has low yield ratio and high Z-direction performance.The comprehensive performance fully meets the standard requirements and the wealth is large.