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大型扁钢锭主要用于生产特厚板,随着钢锭吨位增大,钢锭上部缩孔较深,影响成材率,同时疏松等级高,偏析严重,因此大型扁钢锭的质量问题成为发挥特厚板轧机能力的瓶颈。针对该难题,采用大型钢锭水冷模铸装置,成功地浇注了60 t级大型扁钢锭。钢锭被轧制成220 mm厚钢板,尽管钢种成分为Q345B,但各项性能指标达到了超厚板Q345E-Z35的要求,屈服强度为348~373 MPa,抗拉强度为562~588 MPa,伸长率为17%~28.5%,-40℃横向冲击功为56.57~71.65 J、纵向冲击功为40.76~88.80J,1/2处断面收缩率平均为63.04%,1/4处断面收缩率为57.93%,夹杂物级别总和不超过2.0,晶粒度达到8.0~9.0级。表明该大型扁钢锭水冷模铸技术具备为高品质特厚板提供坯料的能力。
Large flat steel ingot is mainly used for the production of heavy plate, with the increase of ingot tonnage, the upper part of the ingot shrinkage is deep, affecting the finished product rate, while the loose level, segregation serious, so the quality of large flat steel ingot becomes a plate mill Capability bottleneck. In response to this challenge, large-scale ingot water-cooled die-casting device was successfully cast 60 t-class large flat steel ingot. The steel ingot is rolled into a 220 mm thick steel plate. Although the steel composition is Q345B, various performance indexes meet the requirements of the ultra-thick plate Q345E-Z35. The yield strength is 348 to 373 MPa and the tensile strength is 562 to 588 MPa. The elongation is 17% -28.5%, the transverse impact energy at 40 ℃ is 56.57 ~ 71.65 J, the longitudinal impact energy is 40.76 ~ 88.80J, the average reduction of area at 1/2 is 63.04%, the reduction of area at 1/4 57.93%, the total inclusion level does not exceed 2.0, grain size reached 8.0 to 9.0. It shows that the large flat steel ingot water-cooled molding technology has the ability to provide blank for high-quality heavy plate.