Industrial experimental on inclusion characteristics and corrosion resistance of La-Ce treated 75Cr1 steel
MENG Ze1, LI Guangqiang1,2,3, ZHAO Yijiang1, ZHENG Qing4, ZENG Bin4, LIU Yu1
1. The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China; 2. Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China; 3. Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China; 4. Technical Center, Lianyuan Iron and Steel Co., Ltd., Loudi 417009, Hunan, China
Abstract：The saw blade has been in service for a long time under resonance,large lateral pressure,tensile stress and contact with cooling medium,so the saw blade steel is required to have certain elastic strength,fatigue strength,impact toughness and corrosion resistance. Non metallic inclusions in steel can break the continuity of steel matrix,easily cause cracks in steel,and have an important impact on the pitting resistance of steel. The 75Cr1 steel with different rare earth contents were produced by industrial test. The effect of rare earth treatment on the cleanliness and corrosion resistance of 75Cr1 steel was investigated by inclusions characterization,the electrochemical polarization experiments and weight loss experiments. The results show that rare earth can effectively remove O,S elements in steel,modify the inclusions in steel and improve the corrosion resistance of steel matrix. In the 75Cr1 steel without rare earth,the total oxygen mass percent is 0.002 0% and the total sulfur mass percent is 0.001 2%;the typical inclusions are Mg-Al-O oxide inclusions and CaS+MnS inclusions,the average size of inclusions is 2.1 μm;the pitting corrosion potential of steel is -410 mV,and the self-corrosion potential of steel is -1 000 mV. When the mass percent of Ce and La in 75Cr1 steel reaches 0.013 6% and 0.007 2%,the total oxygen mass percent is 0.001 1% and the total sulfur mass percent is 0.000 8%;the typical inclusions is RExSy+CaS and less Al2O3inclusions,the average size of inclusions is 1.7 μm,the number of inclusions shows a decreasing trend,the distribution of inclusions is more dispersed and the morphology of inclusions changes from irregular shape to spherical shape;pitting corrosion potential and self-corrosion potentials of steel are effectively increased,the pitting corrosion potential of steel is -336 mV,and the self-corrosion potential of steel is -981 mV,self-corrosion current and corrosion rate decrease. Thermodynamic calculation showed that RExSy is less soluble than MnS and CaS. Therefore,rare earth treatment can improve the pitting corrosion resistance of 75Cr1 steel. The 75Cr1 steel is a small batch production steel. It avoids the hidden problem of clogging the submersed nozzle during continuous casting after rare earth treatment,so rare earth treatment 75Cr1 steel has strong industrial adaptability.
[1] 刘笛,宋艳青,张鑫,等. La对75Cr1锯片用钢热轧板组织和力学性能的影响[J]. 热加工工艺,2021,50(14):51. (LIU D,SONG Y Q,ZHANG X,et al. Effect of La on microstructure and mechanical properties of 75Cr1 saw blade steel[J]. Hot Working Technology,2021,50(14):51.) [2] 张先菊,胡帅,赵荐伟,等. 国产75Cr1锯片钢热处理工艺研究[J]. 热加工工艺,2021,50(8):124. (ZHANG X J,HU S,ZHAO J W,et al. Study on heat treatment process of domestic 75Cr1 saw blade steel[J]. Hot Working Technology,2021,50(8):124.) [3] TANAKA K,MURA T. A theory of fatigue crack initiation at inclusions[J]. Metallurgical Transactions A,1982,13(1):117. [4] WANG Q Y,BATHIAS C,KAWAGOISHI N,et al. Effect of inclusion on subsurface crack initiation and gigacycle fatigue strength[J]. International Journal of Fatigue,2002,24(12):1269. [5] MAYES I C,BAKER T J. Inclusion-induced anisotropy of fatigue crack growth in steel[J]. Materials Science and Technology,1986,2(2):133. [6] GALL K,HORSTEMEYER M F,DEGNER B W,et al. On the driving force for fatigue crack formation from inclusions and voids in a cast A356 aluminum alloy[J]. International journal of fracture,2001,108(3):207. [7] MELANDER A. A finite element study of short cracks with different inclusion types under rolling contact fatigue load[J]. International Journal of Fatigue,1997,19(1):13. [8] WANG P,WANG B,LIU Y,et al. Effects of inclusion types on the high-cycle fatigue properties of high-strength steel[J]. Scripta Materialia,2022,206:114232. [9] ZHANG J M,LI S X,YANG Z G,et al. Influence of inclusion size on fatigue behavior of high strength steels in the gigacycle fatigue regime[J]. International Journal of Fatigue,2007,29(4):765. [10] 赵一将,李光强,孟泽,等. 不同铝含量的脱氧剂对钢液洁净度的影响[J].钢铁,2023,58(1):47. (ZHAO Y J,LI G Q,MENG Z,et al. Effect of deoxidizer with different Al content on cleanliness of molten steel[J]. Iron and Steel,2023,58(1):47.) [11] 柯伟. 中国腐蚀调查报告[M]. 北京:化学工业出版社,2003. (KE W. China Corrosion Investigation Report[M]. Beijing:Chemical Industry Press,2003.) [12] YUE L J,WANG M,HAN J S. Effects of rare earth on inclusions and corrosion resistance of 10PCuRE weathering steel[J]. Journal of Rare Earths,2010,28(6):952. [13] JIA D,ZHONG L,YU J,et al. Effects of electropulsing on inclusion size and corrosion-resistance of 304 stainless steel[J]. Materials Science and Technology,2020,36(12):1263. [14] SHIBAEVA T V,LAURINAVICHYUTE V K,TSIRLINA G A,et al. The effect of microstructure and non-metallic inclusions on corrosion behavior of low carbon steel in chloride containing solutions[J]. Corrosion Science,2014,80:299. [15] PARK I J,LEE S M,KANG M,et al. Pitting corrosion behavior in advanced high strength steels[J]. Journal of Alloys and Compounds,2015,619:205. [16] YANG S,ZHAO M,FENG J,et al. Induced-pitting behaviors of MnS inclusions in steel[J]. High Temperature Materials and Processes,2018,37(9/10):1007. [17] LI M,WU H,SUN Y. Influence of non-metallic inclusions on corrosive properties of polar steel[J]. Frontiers in Materials,2021,8:602851. [18] SHI C B,CHEN X C,GUO H J,et al. Assessment of oxygen control and its effect on inclusion characteristics during electroslag remelting of die steel[J]. Steel Research International,2012,83(5):472. [19] ZHANG Y,CHENG G,WANG J,et al. Evolution of nonmetallic inclusions in GCr15 bearing steels during continuous casting process[J]. Steel Research International,2022,93(2):2100445. [20] TAVARES S S M,PARDAL J M,MARTINS T R B,et al. Influence of sulfur content on the corrosion resistance of 17-4PH stainless steel[J]. Journal of Materials Engineering and Performance,2017,26(6):2512. [21] LIU Y Q,WANG L J,CHOU K C. Effects of cerium on resistance to pitting corrosion of spring steel used in fasteners of high-speed railway[J]. Steel Research International,2014,85(11):1510. [22] LIU Y Q,WANG L J,KUOCHIH C. Effect of cerium on the cleanliness of spring steel used in fastener of high-speed railway[J]. Journal of Rare Earths,2014,32(8):759. [23] IMASHUKU S,WAGATSUMA K. Cathodoluminescence analysis of nonmetallic inclusions in steel deoxidized and desulfurized by rare-earth metals (La,Ce,Nd)[J]. Metallurgical and Materials Transactions B,2020,51(1):79. [24] WANG H,BAO Y,DUAN C,et al. Effect of rare earth Ce on deep stamping properties of high-strength interstitial-free steel containing phosphorus[J]. Materials,2020,13(6):1473. [25] WANG H,BAO Y,ZHI J,et al. Effect of rare earth Ce on the morphology and distribution of Al2O3 inclusions in high strength IF steel containing phosphorus during continuous casting and rolling process[J]. ISIJ International,2021,61(3):657. [26] 郭湛,完卫国,孙维,等. 含稀土高强度耐腐蚀钢筋的研究[J]. 钢铁,2010,45(12):53. (GUO Z,WAN W G,SUN W,et al. Study on high strength and resisting corrosion steel bar containing Re[J]. Iron and Steel,2010,45(12):53.) [27] 习小军,杨树峰,李京社,等. 含铈304不锈钢夹杂物改性及耐腐蚀性能优化[J]. 钢铁,2020,55(1):20. (XI X J,YANG S F,LI J S,et al. Inclusion modification and corrosion resistance optimization of 304 stainless steel containing cerium[J]. Iron and Steel,2020,55(1):20.) [28] NISHIMOTO M,MUTO I,SUGAWARA Y,et al. Cerium addition to CaS inclusions in stainless steel:Insolubilizing water-soluble inclusions and improving pitting corrosion resistance[J]. Corrosion Science,2021,180:109222. [29] 孟泽,李光强,李腾飞,等. Ce对75Cr1钢洁净度、组织与耐点蚀性影响[J/OL]. 金属学报,[2022-12-01]. https://www.ams.org.cn/CN/10.11900/0412.1961.2022.00359. (MENG Z,LI G Q,LI T F,et al. Effect of Ce on cleanliness,microstructure and pitting corrosion resistance of 75Cr1 steel[J/OL]. Acta Metallurgica Sinica,[2022-12-01]. https://www.ams.org.cn/CN/10.11900/0412.1961.2022.00359.) [30] 刘宏亮. 稀土对X80管线钢组织和性能的影响[D]. 沈阳:东北大学,2011. (LIU H L. Effect of Rare of on Microstructure and Property of X80 Pipeline Steel[D]. Shenyang:Northeastern University,2011.) [31] MITSUTAKA H,KIMIHISA I. Thermodynamic Data for Steelmaking[M]. Sendai:Tohuku University Press,2010. [32] LIU C,REVILLA R I,LIU Z,et al. Effect of inclusions modified by rare earth elements (Ce,La) on localized marine corrosion in Q460 NH weathering steel[J]. Corrosion Science,2017,129:82. [33] NISHIMOTO M,MUTO I,SUGAWARA Y,et al. Micro-electrochemical properties of CeS inclusions in stainless steel and inhibiting effects of Ce3+ ions on pitting[J]. Journal of the Electrochemical Society,2017,164(13):C901. [34] LIU Z,LIAN X,LIU T,et al. Effects of rare earth elements on corrosion behaviors of low-carbon steels and weathering steels[J]. Materials and Corrosion,2020,71(2):258. [35] 汪兵,刘清友,王向东,等. 稀土Ce和La对碳钢在NaCl溶液中的缓蚀机理[J]. 中国腐蚀与防护学报,2007,27(3):151. (WANG B,LIU Q Y,WANG X D,et al. Inhibitive corrosion mechanism of Ce-ion and La-ion for carbon steel in NaCl solution[J]. Journal of Chinese Society for Corrosion and Protection,2007,27(3):151.) [36] CHIBA A,MUTO I,SUGAWARA Y,et al. Pit initiation mechanism at MnS inclusions in stainless steel:Synergistic effect of elemental sulfur and chloride ions[J]. Journal of the Electrochemical Society,2013,160(10):C511.
2023, Vol. 58 
