Effect of TMCP on microstructure and mechanical properties of Ti-Mo-Nb microalloyed low carbon steel

doi:10.13251/j.issn.0254-6051.2023.01.027

Abstract

Abstract: Effect of cooling rate of TMCP on microstructure and mechanical properties of Ti-Mo-Nb microalloyed steel was studied. The results show that as the cooling rate decreases, the ferrite grains become equiaxed and the volume fraction and grain size of the ferrite gradually increase. Reducing the cooling rate can significantly refine the size of the precipitates and increase its volume fraction, and the precipitation behavior changes from dispersive precipitation to interphase precipitation. The precipitation strengthening of ferrite improves the strength of the tested steel, as well as the formability. When the cooling rate is 28 ℃/s, an excellent combination of strength and ductility is obtained as the tensile strength of 853 MPa, the yield strength of 750 MPa, the elongation of 18.6%and the hole expansion rate of 68.5%. The grain refinement strengthening and precipitation strengthening are the main strengthening mechanisms of the tested steel, when the cooling rate is 28 ℃/s, the strength increments of grain refinement strengthening and precipitation strengthening are 206 MPa and 328 MPa, respectively.

Key words: Ti-Mo-Nb steel, precipitation, hole expansion rate, strengthening mechanism

CLC Number:

TG142.1⁺4

Zhang Jincheng, Sun Shenghui, Cai Minghui, Zhao Wenzhu, Ding Hua. Effect of TMCP on microstructure and mechanical properties of Ti-Mo-Nb microalloyed low carbon steel[J]. Heat Treatment of Metals, 2023, 48(1): 155-162.

References

[1]陈俊, 吕梦阳, 唐帅, 等. V-Ti微合金钢的组织性能及相间析出行为[J]. 金属学报, 2014, 50(5): 524-530.
Chen Jun, Lü Mengyang, Tang Shuai, et al. Mechanical properties and interphase precipitation behaviors in V-Ti microalloyed steel[J]. Acta Metallurgica Sinica, 2014, 50(5): 524-530.
[2]Mukherjee S, Timokhina I, Zhu C, et al. Clustering and precipitation processes in a ferritic titanium-molybdenum microalloyed steel[J]. Journal of Alloys and Compounds, 2017, 690(5): 621-632.
[3]汪小培, 赵征志, 赵爱民, 等. Mo含量对Ti微合金低碳钢力学性能的影响[J]. 金属热处理, 2014, 39(10): 47-50.
Wang Xiaopei, Zhao Zhengzhi, Zhao Aimin, et al. Effect of Mo content on mechanical properties of Ti micro-alloyed low-carbon steel[J]. Heat Treatment of Metals, 2014, 39(10): 47-50.
[4]Cheng L, Cai Q W, Yu W. Coarsening of nanoscale (Ti, Mo)C precipitates in different ferritic matrixes[J]. Materials Characterization, 2018, 142: 195-202.
[5]张可, 雍岐龙, 孙新军, 等. 卷取温度对Ti-V-Mo复合微合金化超高强度钢组织及力学性能的影响[J]. 金属学报, 2016, 52(5): 529-537.
Zhang Ke, Yong Qilong, Sun Xinjun, et al. Effect of coiling temperature on microstructure and mechanical properties of Ti-V-Mo complex microalloyed ultra-high strength steel[J]. Acta Metallurgica Sinica, 2016, 52(5): 529-537.
[6]Huang H H, Yang G W, Zhao G, et al. Effect of Nb on the microstructure and properties of Ti-Mo microalloyed high-strength ferritic steel[J]. Materials Science and Engineering A, 2018, 736: 148-155.
[7]孙超凡, 蔡庆伍, 武会宾, 等. 轧制工艺对铁素体基体Ti-Mo微合金钢纳米尺度碳氮化物析出行为的影响[J]. 金属学报, 2012, 48(12): 1415-1421.
Sun Chaofan, Cai Qingwu, Wu Huibin, et al. Effect of controlled rolling processing on nanometer-sized carbonitride of Ti-Mo ferrite matrix microalloyed steel[J]. Acta Metallurgica Sinica, 2012, 48(12): 1415-1421.
[8]Funakawa Y, Shiozaki T, Tomita K, et al. Development of high strength hot-rolled sheet steel consisting of ferrite and nanometer-sized carbides[J]. ISIJ International, 2004, 44: 1945-1951.
[9]Lee W B, Hong S G, Park C G, et al. Carbide precipitation and high-temperature strength of hot-rolled high-strength, low-alloy steels containing Nb and Mo[J]. Metallurgical and Materials Transactions A, 2002, 33(6): 1689-1698.
[10]Hajyakbary F, Sietsma J, Böttger A J, et al. An improved X-ray diffraction analysis method to characterize dislocation density in lath martensitic structures[J]. Materials Science and Engineering A, 2015, 639: 208-218.
[11]Ungár T, Ott S, Sanders P G, et al. Dislocations, grain size and planar faults in nanostructured copper determined by high resolution X-ray diffraction and a new procedure of peak profile analysis[J]. Acta Materialia, 1998, 46(10): 3693-3699.
[12]Hong S G, Yong W K, Kim J H, et al. Effects of rolling temperature on the microstructure and mechanical properties of Ti-Mo microalloyed hot-rolled high strength steel[J]. Materials Science and Engineering A, 2014, 605: 244-252.
[13]Kamikawa N, Ab E Y, Miyamoto G, et al. Tensile behavior of Ti, Mo-added low carbon steels with interphase precipitation[J]. ISIJ International, 2014, 54(2): 474-474.
[14]Yen H W, Chen P Y, Huang C Y, et al. Interphase precipitation of nanometer-sized carbides in a titanium-molybdenum-bearing low-carbon steel[J]. Acta Materialia, 2011, 59(16): 6264-6274.
[15]Chun E J, Do H, Kim S, et al. Effect of nanocarbides and interphase hardness deviation on stretch-flangability in 998 MPa hot-rolled steels[J]. Materials Chemistry and Physics, 2013, 140(1): 307-315.
[16]Kamikawa N, Sato K, Miyamoto G, et al. Stress-strain behavior of ferrite and bainite with nano-precipitation in low carbon steels[J]. Acta Materialia, 2015, 83: 383-396.
[17]Cai M H, Chen L G, Fang K, et al. The effects of a ferritic or martensitic matrix on the tensile behavior of a nano-precipitation strengthened ultra-low carbon Ti-Mo-Nb steel[J]. Materials Science and Engineering A, 2021, 801(11): 140410.
[18]雍岐龙. 钢铁材料中的第二相[M]. 北京: 冶金工业出版社, 2006.
[19]Sarkar B, Jha B K. Development of precipitation strengthened steel with adequate stretch flangeability[J]. Journal of Materials Engineering and Performance, 2011, 20(8): 1414-1418.
[20]Wang R, Garcia C I, Hua H, et al. Microstructure and precipitation behavior of Nb, Ti complex microalloyed steel produced by compact strip processing[J]. ISIJ International, 2006, 46(9): 1345-1353.
[21]Shen Y F, Wang C M, Sun X. A micro-alloyed ferritic steel strengthened by nanoscale precipitates[J]. Materials Science and Engineering A, 2011, 528(28): 8150-8156.
[22]Gladman T. Precipitation hardening in metals[J]. Materials Science and Technology, 1999, 15(1): 30-36.