热轧工艺对不锈钢/铁屑芯包层钢筋性能的影响  

Effect of Hot-Rolling Process on Properties of Stainless Steel/Iron Chips Core Cladding Bar

作　　者：高亚男 张艳菊 郝瑞朝 李金勇 肖宏[3] 

机构地区：[1]河北钢铁集团承钢公司设备部,河北承德067002 [2]河北钢铁集团承钢公司维检中心,河北承德067002 [3]燕山大学国家冷轧板带装备及工艺工程技术研究中心,河北秦皇岛066004

出　　处：《钢铁研究学报》2013年第11期42-48,共7页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(51075353);河北省自然科学基金资助项目(E2010001208)

摘　　要：采用热轧方式,利用回收铁屑制备新型不锈钢/铁屑芯包层钢筋.通过金相显微镜、SEM、EDS及显微硬度仪对不锈钢与铁屑芯的接触界面进行分析,并考察了轧制道次、轧制温度、石墨添加剂等对包层钢筋力学性能的影响.结果显示：经6道次轧制后,界面两侧发生了元素扩散,扩散距离70～80μm,铁屑中的铁向不锈钢中扩散,不锈钢中的Cr、Ni、Mn等元素向铁屑芯中扩散,使界面附近碳钢侧的显微硬度值明显提高.轧制道次的增加,提高了不锈钢与铁屑芯间的结合强度,两金属间的剪切强度最大为355 MPa.随轧制温度的提高,不锈钢/铁屑芯包层钢筋的抗拉强度、仲长率增加.1150和1 250℃轧制的包层钢筋的抗拉强度分别为470和500 MPa,伸长率分别为32％、35％.在铁屑中添加石墨粉可以改善铁屑芯的组织成分.随石墨添加量的增加,包层钢筋的抗拉强度提高,而伸长率降低.石墨添加量为1.0％（质量分数,下同）时,铁屑芯中析出白色网状的二次渗碳体,包层钢筋抗拉强度提高到736.5 MPa,但伸长率降低到16％,拉伸断口呈明显的脆性断裂形貌.The stainless steel/iron chips core cladding bar was hot-rolled by using recycling iron scrap. The interface of the metals and the influence of rolling pass, roiling temperature, graphite additive on properties of stainless steel/iron chips core cladding bar were analyzed by optical microscope, SEM, EDS and micro hardness tester. The experimental results show that element diffusion occurs at the interface after six passes rolling and the width of diffusion zone is about 70--80μm. The Fe of carbon steel diffuses into stainless steel and the Cr, Ni, Mn of stain- less steel diffuse into carbon steel which makes micro hardness of carbon steel near the interface increase obvious- ly. The bonding strength between stainless steel and iron chips core increases with increasing of rolling passes and it is 355 MPa after six passes rolling. The tensile strength and elongation of the cladding bar increase with increas- ing of rolling temperature and they are 470 MPa and 32% at 1 150 ℃, 500 MPa and 35 % at 1250 ℃. The composi- tion of iron chips core is improved by adding graphite powder. With the increasing of the graphite in iron chips, the tensile strength of cladding bar increase, hut decrease for elongation. White reticular secondary cementite is appea- ring when the graphite is 1.0% and the tensile strength is up to 736.5 MPa, the elongation decrease to 16%. The tensile fracture shows brittle fracture morphology.

关 键 词：包层钢筋 不锈钢 铁屑 轧制工艺 

分 类 号：TG335.11[金属学及工艺—金属压力加工]