高强韧及延伸性能耐磨钢NM600关键技术研发与应用  

Development and Application of Key Technologies of NM600 Wear Resistant Steel with Performance of High Strength,High Toughness and High Elongation Ratio

作　　者：刘红艳 王昭东[2] 陈子刚 邓想涛[2] Liu Hongyan;Wang Zhaodong;Chen Zigang;Deng Xiangtao(HBIS Group Hansteel Company;State Key Laboratory of Rolling Technology and Continuous Rolling Automation,Northeast University)

机构地区：[1]河钢集团邯钢公司 [2]东北大学轧制技术及连轧自动化国家重点试验室

出　　处：《宽厚板》2021年第1期6-11,共6页Wide and Heavy Plate

摘　　要：采用Gleeble-3500热模拟试验机对超高强耐磨钢NM600进行试验,研究第1轧程控轧压下率与原始奥氏体晶粒尺寸的关系。结果表明:当单道次压下率范围在15%~25%时,板坯表面和心部同时发生充分的动态再结晶,得到细小原始奥氏体晶粒。根据耐磨钢NM600奥氏体连续冷却转变曲线,设定轧后空冷驰豫开始温度A c _(3)+(30~50)℃,空冷弛豫终止温度为A c _(3)-(30~50)℃,并通过在线控制冷却,以中等冷却速度冷却至640~660℃,调控淬火前的形变奥氏体晶粒尺寸以及铁素体、珠光体组织形态和尺寸;采用控温控速淬火+低温回火工艺,柔性化控制调质处理后板条马氏体的尺寸。所生产NM600耐磨钢组织中的马氏体板条束平均宽度为0.6021~1.7453μm,抗拉强度1890~2135 MPa,-20℃冲击功30~59 J,布氏硬度HBW586~602,延伸率≥10%,实现了高强度、高硬度、高韧性与高延伸性能的良好匹配。Ultra-high strength wear resistant steel NM600 is tested by means of Gleeble-3500 thermal simulation testing machine to study the relationship between the reduction ratio and the prior austenite grain size at the first stage of controlled rolling.The results show that when the single pass reduction ratio ranges between 15%and 25%,complete dynamic recrystallization occurs on the surface and the center of slab simultaneously,thus fine prior austenite grain is obtained.According to the the austenitic continuous cooling transformation curve of NM600 wear resistant steel,the starting temperature of air cooling relaxation after rolling is set to A c _(3)+(30~50)℃,the finishing temperature of air cooling relaxation is set to A c _(3)-(30~50)℃,and the NM600 steel is cooled down to temperatures between 640℃and 660℃at medium cooling rate by in-line controlled cooling,the deformed austenite grain size,the morphology,the size of ferrite and pearlite before quenching are controlled.The size of lath martensite after quenching and tempering is controlled flexibly by temperature and cooling rate controlled process of quenching and low temperature tempering.The NM600 wear resistant steel is produced with the average width of martensite lath bundle from 0.6021μm to 1.7453μm,tensile strength from 1890 MPa to 2135 MPa,impact energy from 30 J to 59 J at-20℃,Brinell hardness from HBW586 to HBW602 and elongation ratio≥10%,which achieves a good matching of high strength,high hardness,high toughness and high elongation ratio.

关 键 词：NM600 形变奥氏体 空冷弛豫工艺 马氏体板条束 延伸率 

分 类 号：TG142.72[一般工业技术—材料科学与工程]