Abstract：When using traditional welding materials for high-strength steels to carry out extensive welding testing of 690 MPa grade copper precipitation strengthening steel,it was still necessary to strictly control the heat input,preheating temperature,and interpass temperature,which makes the excellent performance of copper precipitation strengthening steel and the advantage of saving production cost cannot be brought into full play. The effect of Si,Mn,Ni on the microstructure and mechanical properties of the 690 MPa grade ultra-low carbon bainite (ULCB) deposited metal was investigated by OM,SEM,TEM,in order to provide technical accumulation for domestic production of non-preheating welding materials for copper precipitation strengthening steel. Experimental results showed that the microstructure of deposited metal was primarily comprised of granular bainite (GB),lath bainite (LB),and acicular ferrite (AF). The microstructure of the deposited metal with 0.16% Si and 1.46% Mn was refined, leading to the improvement of impact toughness. However,the Si content was too low to make the width of the bainite ferrite (BF) substructure decreased,resulting in the improvement of toughness was limited. The microstructure of deposited metal with 0.29% Si,1.02% Mn and more Ni content was interlocked,and the lath width of the bainite ferrite decreased,contributing to impact toughness improved significantly. Phase transformation dislocation strengthening was affected by the bainite onset temperature (Bs),which was the main reason that affects the strength of ULCB deposited metal. Inclusions were mainly distributed between the bainite ferrite,and a small amount become the nucleation points of the acicular ferrite. Therefore,a greater increase in impact toughness would be realized by reduction in inclusion density and size of the deposited metal.
[1] 李振团, 柴锋,杨才福,等. 淬火工艺对铜沉淀强化UHS钢组织性能的影响[J]. 钢铁,2019,54(6):79.(LI Zhen-tuan,CHAI Feng,YANG Cai-fu,et al. Effect of quenching process on microstructure and mechanical properties of Cu precipitated hardened ultra-high strength steel[J]. Iron and Steel,2019,54(6):79.) [2] 雷玄威,周栓宝,黄继华. 超高强度船体结构钢焊接性的研究现状和趋势[J]. 材料研究学报,2020,34(1):1.(LEI Xuan-wei,ZHOU Shuan-bao,HUANG Ji-hua. Current status and development trend on weldability of ultra-high strength hull Structure steel[J]. Chinese Journal of Materials Research,2020,34(1):1.) [3] 彭云,王爱华,肖红军,等. Cu对690 MPa级HSLA钢熔敷金属组织形成和细化的作用[J]. 金属学报,2012,48(11):1281.(PENG Yun,WANG Ai-hua,XIAO Hong-jun,et al. Effect of Cu on microstructure forming and refining of weld metal in 690 MPa grade HSLA steel[J]. Acta Metallurgica Sinica,2012,48(11):1281.) [4] 娄宇航,肖红军,彭云,等. 690 MPa级低合金高强钢焊接接头组织性能[J]. 材料科学与工艺,2012,20(2):101.(LOU Yu-hang,XIAO Hong-jun,PENG Yun,et al. Study on microstructure and properties of welded joints of a 690 MPa grade HSLA steel[J]. Materials Science and Technology,2012,20(2):101.) [5] 严春妍,元媛,张可召,等. X100管线钢焊接冷裂纹敏感性[J]. 焊接学报,2019,40(12):41.(YAN Chun-yan,YUAN Yuan,ZHANG Ke-zhao,et al. Welding cold crack sensitivity of X100 pipeline steel[J]. Transactions of the China Welding Institution,2019,40(12):41.) [6] MAO Gao-jun,CAO Rui,YANG Jun,et al. Effect of nickel contents on the microstructure and mechanical properties for low-carbon bainitic weld metals[J]. Journal of Materials Engineering and Performance,2017,26(5):2057. [7] Vassilaros M G,Czyryca E J. The Development of high-strength,cooling-rate insensitive ultra-low-carbon steel weld metals[J]. Key Engineering Materials,1993,84/85:587. [8] 薛小怀,钱百年,国旭明,等. 超低碳贝氏体(ULCB)焊接材料的研究进展[J]. 焊接学报,2001(4):93.(XUE Xiao-huai,QIAN Bai-nian,GUO Xu-ming,et al. Research progress of ultra-low carbon bainite(ULCB) welding materials[J]. Transactions of the China Welding Institution,2001(4):93.) [9] 栗卓新,苏小虎,李红,等. 690 MPa级以上高强钢焊接熔敷金属微观组织及其联合贝氏体的研究进展[J]. 中国材料进展,2019,38(12):1169.(LI Zhuo-xin,SU Xiao-hu,LI Hong,et al. Research progress on microstructure and coalesced bainite of welded deposited metal to high-strength steel with tensile strength above 690 MPa[J]. Materials China,2019,38(12):1169.) [10] 马成勇. 新一代800 MPa级超低碳微合金钢焊材及接头组织性能研究[D]. 天津:天津大学,2003.(MA Cheng-yong. Study on the Welding Material and the Microstructure and Properties of the Welded Joint in a 800 MPa Grade Structural Steel[D]. Tianjin:Tianjin University,2003.) [11] 万响亮,胡锋,成林,等. 残留奥氏体对微纳贝氏体钢塑韧性的影响[J]. 钢铁研究学报,2019,31(3):305.(WAN Xiang-liang,HU Feng,CHENG Lin,et al. Effect of retained austenite on plasticity and toughness of micro/nano bainitic steel[J]. Journal of lron and Steel Research,2019,31(3):305.) [12] 牛延龙,刘清友,贾书君,等. X80级高强低合金管线钢组织与冲击韧性[J]. 钢铁,2019,54(2):67.(NIU Yan-long,LIU Qing-you,JIA Shu-jun,et al. Microstructure and impact toughness of X80 grade high strength low alloy pipeline steel[J]. Iron and Steel,2019,54(2):67.) [13] 王学林,董利明,杨玮玮,等. Mn/Ni/Mo配比对K65管线钢焊缝金属组织与力学性能的影响[J]. 金属学报,2016,52(6):649.(WANG Xue-lin,DONG Li-ming,YANG Wei-wei,et al. Effect of Mn,Ni,Mo proportion on microstructure and mechanical properties of weld metal of K65 pipeline steel[J]. Acta Metallurgica Sinica,2016,52(6):649.) [14] 赵乃勤. 合金固态相变[M]. 长沙:中南大学出版社,2008.(ZHAO Nai-qin. Solid Phase Transformations in Alloys[M]. Changsha:Central South University Press,2008.) [15] 于少飞,钱百年,国旭明. ULCB熔敷金属组织与碳、氧含量对力学性能的影响[J]. 金属学报,2005(10):76.(YU Shao-fei,QIAN Bai-nian,GUO Xu-ming. Microstructure of ULCB deposited metal and effect of carbon and oxygen contents on mechanical property[J]. Acta Metallurgica Sinica,2005(10):76.) [16] Singh,Daya. Microstructure and Properties of Ultra Low Carbon Bainitic Steel Weld Metal for HSLA-100[D]. Washington:Oregon Graduate Institute of Science and Technology,1996. [17] Zhang Z,Farrar R A. Influence of Mn and Ni on the microstructure and toughness of C-Mn-Ni weld metals[J]. Welding Journal,1997,76(5):183. [18] 万响亮,李光强,吴开明. 低合金高强钢针状铁素体组织特征和形成机理[J]. 钢铁研究学报,2016,28(6):1.(WAN Xiang-liang,LI Guang-qiang,WU Kai-ming. Microstructure characteristics and formation mechanism of acicular ferrite in high-strength low-alloy steels[J]. Journal of Iron and Steel Research,2016,28(6):1.) [19] 安同邦,魏金山,单际国,等. 保护气成分对1 000 MPa级高强熔敷金属组织特征的影响[J]. 金属学报,2019,55(5):575.(AN Tong-bang,WEI Jin-shan,SHAN Ji-guo,et al. Influence of shielding gas composition on microstructure characteristics of 1 000 MPa grade deposited metals[J]. Acta Metallurgica Sinica,2019,55(5):575.) [20] 卓晓,安同邦,马成勇. 420 MPa级耐候桥梁钢用焊材熔敷金属强韧化规律[J]. 钢铁,2020,55(4):88.(ZHUO Xiao,AN Tong-bang,MA Cheng-yong. Strengthening and toughening mechanisms of deposited metals for 420 MPa weathering bridge steel[J]. Iron and Steel,2020,55(4):88.) [21] 刘军,宋朝琦,刘杰,等. H08A焊丝钢夹杂物演变规律分析[J]. 中国冶金,2021,31(3):44.(LIU Jun,SONG Zhao-qi,LIU Jie,et al. Analysis on evolution law of inclusions in H08A wire steel[J]. China Metallurgy,2021,31(3):44.)
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