Nb-Ti-V微合金化船板钢的高温力学性能研究

采用Gleeble-3500热模拟试验机研究D36船板钢连铸板坯的高温力学性能,用扫描电镜观察断口形貌,并分析脆化机理。结果表明:不含钒的铸坯第Ⅰ脆性温度区大于1 350℃;其在1 350～950℃时断面收缩率大于80%,具有良好的高温塑性;第Ⅲ脆性温度区为950～600℃,此时试样断面收缩率处于41.7%～64%。含钒的铸坯第Ⅰ脆性温度区为熔点至1 250℃;在1 250～950℃范围内,塑性较好;其第Ⅲ脆性温度区为950～600℃,此时断面收缩率在34%～73%。为预防铸坯矫直过程裂纹产生,要控制矫直温度在950℃以上。

Research on High Temperature Mechanical Properties of Nb-Ti-V Microalloyed Steel for Ship Plate

High temperature mechanical properties of continuously cast slabs of D36 steel for ship plate were tested by Gleeble-3500 thermomechanical simulator.The morphology of its fracture surface was analyzed by SEM,and its brittleness mechanism was also studied.The results showed that: the brittleness temperature range Ⅰ of the 373# steel slab containing no vanadium was over 1 350 ℃.In the range of 1 350～950 ℃,the slab has a reduction of area over 80% with good high-temperature plasticity.The brittleness temperature range Ⅲ of the specimen was 950～600 ℃ with its reduction of area in the range of 41.7% ~64%.The brittleness temperature range Ⅰ of the 374# steel slab containing vanadium was from melting point to 1 250 ℃,which exhibited good high-temperature plasticity at 1 250～950 ℃.Its brittleness temperature region Ⅲ was 950～600 ℃with reduction of area of 34%~73%.In order to prevent cracking during straightening,the straightening temperature for the slabs should be controlled over 950 ℃.