温度及应变速率对Q235B钢连铸坯高温力学性能的影响  

Effect of Temperature and Strain Rate on High Temperature Mechanical Properties of Q235B Steel Continuous Casting Billet

作　　者：罗龙[1] 李丽荣[2] 黄丽颖[3] 定巍[4] 

机构地区：[1]内蒙古科技大学分析测试中心,内蒙古包头014010 [2]内蒙古科技大学数理与生物工程学院,内蒙古包头014010 [3]邢台职业技术学院资源与环境工程系,河北邢台054035 [4]内蒙古科技大学材料与冶金学院,内蒙古包头014010

出　　处：《热加工工艺》2014年第10期79-81,84,共4页Hot Working Technology

摘　　要：采用Gkeble．1500D热／力模拟试验机对Q235B连铸坯高温力学性能进行了测试。测试了试验温度为950℃，应变速率分别为1×10-3、5×10-3、1×10-2、5×10-2S-1时Q235B钢连铸坯的高温力学性能，以及应变速率为5×10-3S-1的条件下。测试温度在700～1000℃时Q235B钢连铸坯的高温力学性能。结果表明：Q235B钢连铸坯的高温抗拉强度和屈服强度随应变速率的升高而增大，而断面收缩率随着应变速率的升高则降低；应变速率对Q235B钢连铸坯高温强度的影响分为敏感区和不敏感区，温度为950℃时，临界应变速率占。为1×10-2S-1；随温度升高，Q235B钢连铸坯的高温抗拉强度和屈服强度均降低，Q235B钢连铸坯的断面收缩率Z随温度的升高总呈上升趋势；在850-950℃内出现了脆化区，在900℃左右时，Z值为58％；温度对硬化指数n的影响较为复杂，硬化指数n随应变速率的增大而降低。The high-temperature mechanical properties of Q235B slab was tested by using Gleeble-1500D experiment machine. The high-temperature mechanical properties of Q235B slab was tested at 950℃ under strain rate of 1 × 10-3, 5 x 10-3, 1×10-2, 5×10-2s-1, respectively, and strain rate is 5×10-3s-1 under 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃ and 1000 ℃. The results show that, high temperature tensile strength and yield strength of Q235B slab increase with the increase of strain rate, the reduction of area decreases with the increase of strain rate. The effect of strain rate on high-temperature mechanical properties of Q235B slab can be divided into sensitive area and no sensitive area. When the temperature is 950℃, the critical strain rate is 1 ×10-2 s-1. With the increase of temperature, high temperature tensile strength and yield strength of Q235B slab reduce. The reduction of area Z of Q235B slab increases with the increase of temperature. Brittle zone appears at 850 ℃ -950 ℃, Zvalue of 58% is 900 ℃. The influence of temperature on the hardening exponent n is more complicated, and, along with the increase of strain rate, the hardening exponent n decreases.

关 键 词：Q235B钢连铸坯 高温力学性能 硬化指数 应变速率 

分 类 号：TG113.25[金属学及工艺—物理冶金]