摘要
研究焊接热模拟工艺参数 (峰值温度Tmax和焊后冷却时间t8/ 5)对低碳微合金Ti-Nb钢 (STE35 5钢 )热影响区 (HAZ)显微组织及冲击韧度的影响。选用干涉层腐蚀法 ,在光学金相显微镜下清晰显示出了显微组织中的粒贝及M -A组元。观察了Tmax和t8/ 5不同的热模拟试样中粒贝及M -A组元的形态及分布特征 ,研究了不同Tmax及t8/ 5参数对显微组织及冲击韧度的影响 ,并用电子显微镜进行了观察和验证。结果表明 ,热模拟峰值温度的升高 ,或冷却趋缓 ,都使显微组织变粗、韧性降低。沿晶铁素体和晶内铁素体片的长大、增厚 ,粒贝中块状M -A岛的长大 ,都对韧性的改善不利。
The effects of technology parameters of stimulated welding thermal cycle (peak temperature T max and cooling time t 8/5 ) on microstructures and impact toughness of HAZ in low carbon microalloying Ti Nb steel STE355 were studied.The microstructures were etched by special interference technology and granular bainite and M A constitucents were shown clearly in optical microscope.The observations were proved by electron microscope.The results show that coarsening of microstructures and decrease of toughness must take place with raising T max and increasing t 8/5 (lowering cooling rate).Growing and thickening of ferrite in boundary and in grains and growing of M A constituents are detrimental to toughness improvement.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2003年第2期55-58,共4页
Transactions of The China Welding Institution
基金
安徽省教育厅自然科学研究资助项目 (2 0 0 0j1191)
关键词
STE355钢
显微组织
焊接
韧性
M-A组元
welding
microalloying Ti Nb steel
microstructure
M A constituent
toughness
