大型扁钢锭水冷制造技术

 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40.76～88.80 J，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。

Technology for Large Rectangular Ingot Production With Intensive Water Cooling

Large ingots are mainly used for production of supper thickness plates . With the increasing of ingot mass, the porosity is so deep on the upper of ingot that the metal yield is reduced, and the organization density is relatively poor and segregation is serious. So the large-rectangular ingot quality becomes the bottleneck to play heavy plate mill capacity. Aim at the problem , the equipment for casting large ingot with intensive water cooling was used to produce a kind of large rectangular ingot with 60 t successfully. The ingot was rolled into 220 mm thick steel plate. Although the composition is in the range of Q345B, the performance indexes met the stand of super thickness Q345E-Z35 plate, and the yield strength was 348 to 373 MPa, the tensile strength was 562 MPa to 588 MPa, percentage elongation was 17% to 28.5%, the transverse impact energy was 56.57 to 71.65 J and the longitudinal impact energy was 40.76 to 88.80 J at －40 ℃, the average percentage reduction in area was 63.04% at 1/2 thickness and 57.93% at 1/4 thickness .The total inclusions grade was not exceed 2.0, the grain fineness was 8 to 9. The result shows that the technology for production large rectangular ingot with intensive water cooling can provide the stocks for super thickness plates.