TMCP工艺冷速对FH40低温船舶用钢组织与性能的影响  

EFFECT OF COOLING RATE OF TMCP PROCESS ON MICROSTRUCTURE AND PROPERTIES OF FH40 LOW TEMPERATURE MARINE STEEL

作　　者：马国金 何元春[1] 董占斌[1] 许藏文 魏运飞 Ma Guojin;He Yuanchun;Dong Zhanbin;Xu Cangwen;Wei Yunfei(Shougang Jingtang Iron and Steel United Co.,Ltd.,Tangshan 063200,Hebei)

机构地区：[1]首钢京唐钢铁联合有限责任公司,河北唐山063200

出　　处：《河北冶金》2022年第11期27-31,共5页Hebei Metallurgy

摘　　要：通过动态CCT曲线研究了不同冷速对特厚FH40低温船舶用钢显微组织的影响。当冷速小于0.5℃/s时,金相为PF+P组织;当冷速在1~5℃/s之间时,金相为PF+AF组织;当冷速大于5℃/s时,金相为AF+GB组织。结合研究成果,确定了获得目标组织PF+AF的TMCP工艺参数。工业试制结果表明,TMCP工艺试制的80mm特厚FH40低温船舶用钢塑性和低温韧性满足GB/T 712-2011标准要求,钢板NDT落锤合格温度为-65℃;厚度1/4位置的韧性—脆性转变温度在-80℃左右,心部的韧性—脆性转变温度在-70℃左右;心部韧性差主要是因为心部的GB组织导致大于15°的大角度晶界比厚度1/4处低5.6%,大角度晶界减少不利于低温韧性。The effect of different cooling rates on the microstructure of extra-thick FH40 low temperature marine steel was studied by dynamic CCT curve.When the cooling rate is less than 0.5℃/s,the microstructure is PF+P,when the cooling rate is between 1℃/s and 5℃/s,the microstructure is PF+AF,and when the cooling rate is more than 5℃/s,the microstructure is AF+GB.Based on the research results,the TMCP process parameters of PF+AF were determined.The results of industrial trial production show that the plasticity and low temperature toughness of 80 mm extra-thick FH40 low temperature marine steel produced by TMCP process meet the requirements of GB/T 712-2011,and the qualified temperature of NDT drop weight of steel plate is-65℃;The ductile-brittleness transition temperature at the position of 1/4 thickness is about-80℃,and the ductile-brittleness transition temperature at the center is about-70℃.The poor taughness in the heart is mainly clue to the GB structure inside,resulting in a high-angle grain boundary louered by 5.6%than at 1/4 of the thickness.The decress of the grain boundary with large angle is unfavorable to the low temperafure toughness.

关 键 词：FH40 CCT曲线 低温船舶用钢 TMCP 显微组织 

分 类 号：TG142.1[一般工业技术—材料科学与工程]