210 MPa级别新型冷轧搪瓷用钢的组织及性能

Microstructure and properties of the 210 MPa grade new cold-rolled steel for enameling

针对电热行业向着低成本、绿色环保和高安全性能方向发展的趋势,开发了210 MPa级别新型冷轧搪瓷用钢。研究了模拟搪烧工艺对试验钢组织性能的影响;结合湿法搪瓷工艺,对比了在简化的搪前处理工艺下试验钢和对比钢的密着性能;采用电化学方法测定了试验钢的抗鳞爆性能。结果表明:显微组织主要由等轴状铁素体和少量珠光体组成,经850℃、不超过15 min的条件下模拟搪烧,试验钢防止晶粒粗化的能力较强,屈服强度仍可保持在210 MPa以上;在盐酸或硫酸更换为有机酸、免除披镍处理的条件下,试验钢和瓷釉在搪烧后形成了含有Fe、Si、O、Ni、Co、Cr、K等元素的粗糙界面,极大改善了钢板与搪瓷层的结合强度;试验钢的平均氢渗透值超过6.7 min/mm^(2),具有优异的贮氢性能。

With the development trend of low cost,green environment protection,and high security performance of the electric heating industry,the 210 MPa grade new cold-rolled steel for enameling was developed.The influence of simulated enamel firing process on mechanical properties and microstructure of the experimental steel was investigated.Combined with the wet enameling process,the adherence of the experimental steel and the contrast steel under the condition of the simplified pretreatment process was compaired.The resistance to fish-scale was evaluated through electrochemical method.The results show that,the annealed steel consists of equiaxial ferrite and a small quantity of pearlite.After simulated enamel firing at 850℃for no more than 15 min,the experimental steel has a strong ability to prevent grain coarsening and the yield strength is above 210 MPa.Under the conditions of replacing hydrochloric acid or sulfuric acid with organic acid and eliminating nickel treatment,a rough interface containing Fe,Si,O,Ni,Co,Cr,K and other elements was formed,which greatly improves the bonding strength between the steel and the enamel layer.The average hydrogen permeation value exceeds 6.7 min/mm^(2),so the investigated steel has excellent resistance to fish-scale.