论文部分内容阅读
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355MPa。随轧制温度的提高,不锈钢/铁屑芯包层钢筋的抗拉强度、伸长率增加。1 150和1 250℃轧制的包层钢筋的抗拉强度分别为470和500MPa,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736.5MPa,但伸长率降低到16%,拉伸断口呈明显的脆性断裂形貌。
Using hot rolling method, the use of recycled scrap iron preparation of new stainless steel / iron core cladding steel. The contact interface between stainless steel and iron scrap core was analyzed by metallographic microscope, SEM, EDS and microhardness tester. The influence of rolling pass, rolling temperature and graphite additive on the mechanical properties of clad steel was investigated. The results show that elemental diffusion occurs on both sides of the interface after rolling for 6 passes with the diffusion distance of 70 ~ 80μm. The iron in the iron filings diffuses into the stainless steel. Elements such as Cr, Ni and Mn in the stainless steel diffuse into the stainless steel. Diffusion, so that the interface near the carbon steel hardness increased significantly. The increase of rolling pass improves the bonding strength between stainless steel and iron filings, and the maximum shear strength between the two metals is 355 MPa. With the increase of the rolling temperature, the tensile strength and elongation of the stainless steel / iron scrap core cladding tendons increase. The tensile strengths of the cladding bars rolled at 1 150 and 1 250 ℃ were 470 and 500 MPa respectively, and the elongation rates were 32% and 35%, respectively. The addition of graphite powder to the scrap iron can improve the texture of the scrap iron core. With the increase of graphite addition, the tensile strength of clad steel increases, while the elongation decreases. When the addition amount of graphite is 1.0% (mass fraction), the secondary reticular cementite with white reticular precipitated in the iron scrap core, the tensile strength of clad steel increases to 736.5MPa, but the elongation decreases to 16% Tensile fracture showed obvious brittle fracture morphology.