Zr微合金化HSLA钢粗晶热影响区的组织和性能

用焊接热模拟法研究了Zr处理对 (%):≤ 0.18C-1.2～1.6Mn低合金高强度(HSLA)钢焊接粗晶热影响区(CGHAZ)组织和性能的影响。试验结果表明,Zr含量在0.01%～0.03%时,经过30～100kJ/cm线能量焊接热模拟后,CGHAZ的强度、塑性和-50℃冲击韧性都高于没有经过Zr处理的试验钢;Zr钢显微硬度(HV10)177～251,具有优良的焊接性。焊接线能量相同时,没有经过Zr处理试验钢CGHAZ的晶粒比Zr处理钢粗大;焊接线能量为 30kJ/cm时 ,各试验钢CGHAZ的组织以贝氏体为主 ,随着焊接线能量提高 ,CGHAZ中出现针状铁素体和少量珠光体。

Structure and Properties of Coarse Grain Heat Affected Zone of Zr Microalloying HSLA Steel

The effect of micro Zr on structure and mechanical properties of welding coarse grain heat affected zone (CGHAZ)of ≤0.18C-1.2～1.6Mn HSLA steel has been studied by welding thermal simulation method. The test results showed that with 30~ 100 kJ/cm heat input welding thermal simulation,the strength,plasticity and impact toughness at -50 ℃ of CGHAZ of steel containing 0.01%～0.03% Zr were higher than that steel non-containing Zr,and microhardness HV10 value of Zr steels was 177~251.The Zr steels had excellent weldablity and at same heat input the grain in CGHAZ of non-containing steel was coarser than that of Zr steel and with heat input of 30 kJ/cm the bainite was dominant in structure of CGHAZ while with increasing the heat input the acicular ferrite and few pearlite occured in CGHAZ.