基于高温蠕变特性的连铸坯新矫直技术

摘要/Abstract

摘要： 基于目前工厂常用的连铸坯矫直技术，考虑连铸坯在高温下的蠕变特性，提出利用高温蠕变对连铸坯进行蠕变矫直的新观点。针对某钢厂R9300连铸机设计了一条新型的曲率变化满足正弦规律且弯曲段和矫直段弧长显著延长的矫直曲线，通过数值模拟计算和对比分析，新矫直曲线的应变速率更低，矫直过程中可以充分利用材料的高温蠕变性能。通过在Gleeble-3800型热/力模拟试验机上对Q460E钢进行热塑性试验和蠕变拉伸试验，确定了该钢种的相关热物性参数和蠕变本构方程。由于新曲线矫直区的应变速率接近最小蠕变应变速率，连铸坯主要依靠高温蠕变变形进行矫直，降低了应变速率，可以避免连铸坯内部裂纹缺陷，有利于提高连铸坯的质量。
A new straightening technology where the continuous casting slabs might be straightened by full using of high-temperature creep properties was proposed based on the straightening technologies that widely used currently. The new straightening curves were designed herein where the curvatures were changed as sine law. The arc lengths of straightening segments and bending segments were extended significantly. The strain rate in the new curve was less than creep strain rate so that high-temperature creep behavior might be used fully in the straightening processes by finite element method. The parameters of thermo-physical property were confirmed and the creep constitutive equation was derived through the uniaxial tensile tests of Q460E steels on the Gleeble-3800 machine. Strain rates in the new curve were close to the minimum creep strain rates, thus the slabs might be straightened by creep deformations mainly. Due to the lower strain rates, internal cracks caused by bending and straightening might be effectively avoided, and the quality of the slabs was improved.
continuous casting slab; creep straightening; strain rate; straightening curve

关键词: 连铸坯, 蠕变矫直, 应变速率, 矫直曲线

Abstract: New Straightening Technology of Continuous Casting Slabs Based on High-temperature Creep Properties

中图分类号:

张兴中, 郭龙, 冯常喜. 基于高温蠕变特性的连铸坯新矫直技术[J]. 中国机械工程.

ZHANG Xingzhong, GUO Long, FENG Changxi. [J]. China Mechanical Engineering.

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