·134 北京科技大学学报 2004年第2期 5 Savage JA.Theory of heat transfer and air gap formation 6 Mahapatra R B,Brimacombe JK.Mold behavior and its in continuous casting moulds [J].J Iron Steel Inst,1962 influence on quality in the continuous casting of slabs: (1):41 Part 1 [J.Metall Trans B,1991(12):861 Numerical simulation of Liquid Steel Solidification in Slab Molds ZHANG Jiongming",ZHANG Li,YANG Huitao",WANG Xinhua 1)Metallurgical and Ecological Engineering School,University of Science and Technology Beijing.Beijing 100083,China 2)Technology Center of Baosteel,Shanghai 201941,China ABSTRACT A mathematical model was proposed to calculate the stress distribution of the solidification shell in a slab mold based on the local heat flux calculated by using the measured temperature of the copper plate.Solidific- ation equations to liquid steel were built and discreted by the finite element method.ANSYS commercial software was used to solve these discrete equations,the stress and strain distributions were obtained and the taper of the mold was decided according to these calculating results. KEY WORDS slab mold;stress distribution;taper (Journal of University of Science and Technology Beijing,Volume 11,Number 1,February 2004,Page 62) Elevated-temperature properties of one long-life high-strength gun steel Maoqiu Wang,Han Dong,and Qi Wang Division of Structural Materials,Central Iron Steel Research Institute,Beijing 100081,China ABSTRACT The hardness,tensile strength and impact toughness of one quenched and tempered steel with nom- inal composition of Fe-0.25C-3.0Cr-3.0Mo-0.6Ni-0.1Nb(mass fraction)both at room temperature and at elevated temperatures were investigated in or-der to develop high-strength steel for long-life gun barrel use.It is found that the steel has lower decrease rate of tensile strength at elevated temperature in comparison with the commonly used G4335V high-strength gun steel,which contains higher Ni and lower Cr and Mo contents.The high elevated-tem- perature strength of the steel is attributed to the strong secondary hardening effect and high tempering softening re- sistance caused by the tempering precipitation of fine Mo-rich M,C carbides in the a-Fe matrix.The ex-perimental steel is not susceptible to secondary hardening embrittlement,meanwhile,its room-temperature impact energy is much higher than the normal requirement of impact toughness for high strength gun steels.Therefore,the steel is suitable for production of long-life high-strength gun barrels with the combination of superior elevated-temperature strength and good impact toughness. KEY WORDS secondary hardening steel;elevated-temperature strength;hot hardness;impact toughness￾ ￾￾￾ ￾ 北 京 科 技 大 学 学 报 ￾￾￾￾年 第 ￾期 ￾ ￾￾￾￾￾ ￾￾ ￾ ￾ ￾￾￾ ￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾ ￾即 ￾￾￾￾￾￾ ￾￾ ￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾ ￾￾￾ ￾ ￾￾￾￾ ￾￾￾￾￾￾￾￾ ， ￾￾￾￾ ￾￾￾ ￾ ￾￾ ￾ ￾￾￾￾￾￾￾ ￾ ￾ ， ￾￾加￾￾￾￾￾ ￾￾ ￾ ￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾ ￾￾￾￾￾￾ ￾ ￾￾￾￾ ￾ ￾￾ ￾￾￾￾￾￾￾￾ ￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾ ￾￾月 ￾ ￾￾￾￾￾￾￾￾ ￾ ， ￾￾￾￾￾￾￾￾￾ ￾￾￾ ￾￾ ￾￾￾￾￾￾￾￾￾￾ ￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾ ￾￾￾￾￾ ￾￾ ￾￾￾ ￾￾￾￾￾ 刀朔刀￾ ￾ ￾￾阴 动岁 ，， 乙队￾￾￾ ￾￾ ， ￾￾￾ ￾￾￾￾￾￾， 牙还脚￾￾￾￾砂 ￾￾￾￾园￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾ ， ￾山￾￾￾￾ ￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾ ￾￾￾￾ ， ￾￾￾￾ ￾￾￾￾￾￾ ， ￾￾ ￾ ￾￾￾￾￾￾￾￾留 ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ， ￾￾￾￾￾ ￾￾￾￾￾￾ ， ￾￾￾￾ ￾￾￾￾￾￾￾￾ ￾ ￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾ ￾￾ ￾￾ ￾￾￾￾￾￾ ￾￾ ￾￾￾ ￾￾￾￾￾￾￾￾￾ ￾￾￾￾ ￾ ￾￾￾ ￾￾￾ ￾￾￾￾￾￾ ￾ ￾￾￾￾￾￾￾￾ ￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾ ￾￾￾￾￾￾￾￾￾ ￾ ￾￾￾￾ ￾￾￾ ￾￾￾ ￾￾￾￾￾￾￾￾ ￾￾ ￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾ ￾￾￾￾￾ ￾￾￾ ￾￾ ￾￾￾￾￾ ￾ ￾￾￾￾￾￾￾刃。￾￾￾￾ ￾￾丘￾￾￾ ￾ ￾￾￾￾￾￾ ￾￾￾￾ ￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾， ￾￾￾ ￾￾ ￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾ ￾ ￾￾￾￾￾ ￾￾￾ ￾ ￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾ ￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾ ￾￾￾ ￾￾￾￾￾ ￾￾￾ ￾￾￾￾￾￾加 ￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾为“￾￾ ￾￾￾￾￾妙 ￾￾￾扭￾￾ ￾￾￾￾￾￾￾￾匆母 ，￾￾扩翻紧 玲才“脚￾ ￾￾，八勺￾￾￾ ￾ ， 不飞云￾￾理 ￾￾￾， 月￾ ￾ ￾￾￾￾￾￾￾ 一 ￾￾￾￾￾￾￾￾ ￾ ￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾ ￾￾￾￾ 一 ￾￾ ￾￾￾ 一 ￾￾￾￾￾￾ ￾￾ ￾￾￾￾ 人勿￾￾￾￾ 肠 ￾￾， 厂￾￾ ￾￾￾， ￾￾￾￾￾肠 ￾￾ ￾￾￾￾￾￾ ￾肠 ￾￾￾￾￾￾人匆￾￾￾ ， ￾ ￾￾￾￾￾ ￾ 浅 ￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾， ￾￾￾’￾ ￾￾￾￾￾￾ ， ￾￾￾ ￾￾￾￾￾￾￾￾ ￾ ￾ ￾￾￾￾￾￾， ￾￾￾￾￾ ￾￾ ￾￾由 ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾初￾ ￾￾￾ ￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾一 ￾ ￾ ￾￾￾ 一 ￾ ￾ ￾￾￾一￾ ￾ ￾￾￾一￾ ￾ ￾￾ 一 ￾ ￾ ￾￾￾ ￾ ￾￾￾ ￾ ￾￾￾￾￾￾￾￾ ￾ ￾￾￾￾ ￾￾￾￾￾￾￾理￾ ￾￾￾ ￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾ ￾￾ ￾￾￾￾￾￾￾￾￾￾ ￾￾￾ ￾￾ ￾￾￾￾叩 ￾￾ 一￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾ 一 ￾￾ ￾￾ ￾￾￾￾￾ ￾ ￾￾￾￾ ￾￾￾￾￾￾ ￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾ ￾￾￾￾￾￾￾￾ ￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾奴犷￾ ￾￾ ￾￾￾￾硕￾￾￾ ￾￾ ￾ ￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾ ￾￾ 一￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾ ， ￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾ ￾￾￾￾￾￾￾￾ ￾￾ ￾￾￾￾ ￾￾￾￾￾￾￾￾ ￾ ￾ ￾ ￾￾ ￾￾￾￾￾￾￾ 一￾￾ ￾ ￾￾￾￾奴￾￾ ￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾ ￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾ ￾￾￾￾ ￾￾￾￾ ￾￾￾￾￾￾ ￾￾￾￾￾口￾￾ ￾ ￾￾￾￾ ￾￾ ￾￾ ￾￾￾￾￾￾ ￾￾￾￾￾ ￾￾￾￾￾￾￾￾ ￾￾ ￾￾￾￾￾ ￾￾一￾￾￾从￾ ￾￾￾￾￾￾ ￾￾ ￾ ￾一￾￾ ￾￾￾￾ ￾ ￾￾￾ ￾ ￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾ ￾￾ ￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ， ￾￾￾￾胃￾￾￾￾， ￾￾ ￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾ ￾￾￾￾￾ ￾￾ ￾￾￾￾￾￾ ￾￾ ￾￾ ￾￾￾ ￾￾￾￾￾￾￾ ￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾ ￾￾￾ ￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾ ￾ ￾五￾￾￾￾￾￾， ￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾ 一￾￾ ￾￾￾ 一￾￾ ￾￾￾￾￾￾ ￾￾ ￾￾￾￾ ￾￾ ￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾杏￾￾￾￾￾￾￾￾叮￾ ￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾ · ￾￾￾ ￾￾￾￾￾ ￾￾￾￾￾￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾ 一￾￾ ￾￾￾￾叮￾ ￾￾ ￾￾￾￾￾￾￾￾￾￾￾￾￾￾￾ ￾￾￾￾￾￾砂￾￾￾￾