朱振强等:应变幅对H13热作模具钢等温疲劳行为的影响 661· 试样,说明应变会加速疲劳过程中材料的软化:无 high pressure die casting applications.Int/Fatigue,2019,119: 论有无应变幅,随着循环时间的增加,试样硬度都 126 会下降,也说明等温疲劳实验是循环软化的过程 [5]Bombac D.Gintalas M,Kugler G,et al.Thermal fatigue behaviour of Fe-1.7C-11.3Cr-1.9Ni-1.2Mo roller steel in temperature range 试样由表及里的硬度差值不大,可以反映出在疲 500-700℃.Int J Fatigue,2019,121:98 劳实验过程中疲劳试验机温差控制的较好,减小 [6] Lu Y,Ripplinger K.Huang XJ,et al.A new fatigue life model for 了心表温差造成的硬度差值 thermally-induced cracking in H13 steel dies for die casting.J 500 Mater Process Technol,2019,271:444 [7]Liu B,Wang B,Yang X D,et al.Thermal fatigue evaluation of 450 AISI H13 steels surface modified by gas nitriding with pre-and post-shot peening.App/Suf Sci,2019,48:45 -△c2=0(18.6h)-■-△x2=0.7%(18.6h) [8]Ghusoon R M,Rawaa H M,Basim HA.Effect of die geometry on ◆-△x/2=0(11.4h) -。-△82=1.1%(13.1h) thermal fatigue of tool steel in aluminium alloy die-casting./OP 4-△cJ2=0(13.1h) -▲-△c/2=0.9%(11.4h) 300 Conf Ser Mater Sci Eng,2019,518(3):032042 [9]Girisha V A,Joshi MM,Kirthan L J,et al.Thermal fatigue 250 analysis of H13 steel die adopted in pressure-die-casting process. Sadhana,.2019,44:148 200 0 0.51.01.52.02.5 3.0 [10]Meng C,Wu C,Wang X L,et al.Effect of thermal fatigue on Distance from the surface/mm microstructure and mechanical properties of H13 tool steel 图9等温疲劳试样显微硬度 processed by selective laser surface melting.Metals,2019,9(7): Fig.9 Microhardness of isothermal fatigue specimen 773 [11]Wu X C,Xu L P.Quantitative analysis and evaluation of the 3结论 Uddeholm heat-checking scale.Plys Test Chem Anal Part A, (1)H13钢的600℃等温疲劳实验中,在0.7% 2002,38(1):14 (吴晓春,许珞萍.Uddeholm热疲劳图谱的分析与定量评定.理 0.9%和1.1%三种不同应变幅下,应变幅越大,试 化检验-物理分册,2002,38(1):14) 样疲劳寿命越短,1.1%应变幅试样的寿命仅为0.7% [12]Ma Y,Wang H,Chai X.et al.Thermal fatigue behavior of HHD 应变幅的61.2%. hot work tool steel with structures.Mater Sci Eng Technol,2018, (2)应变促进裂纹扩展,1.1%应变幅试样主裂 49(12):1494 纹更明显、裂纹宽度更大、扩展长度更长:应变增 [13]Zuo P P.Wu X C.Zeng Y,et al.In-phase and out-of-phase 强氧化作用,应变幅越小,在高温下暴露时间越 thermomechanical fatigue behavior of 4Cr5MoSiVI hot work die 长,氧化层覆盖情况越严重 steel cycling from 400 C to 700 C.Fatigue Fract Eng Mater (3)等温疲劳试样组织有长大和粗化,应变对 Struct,,2018.41(1):159 碳化物析出有助力作用,1.1%应变幅试样碳化物 [14]Gruning A,Lebsanft M.Scholtes B.Isothermal and thermal fatigue of tool steel AISI H11.Mater Sci Forum,2010,638-642: 较0.7%应变幅试样平均直径小8.5%,数量多36.3%. 3230 [15]Gruning A,KrauB M,Scholtes B.Isothermal fatigue of tool steel 参考文献 AISI H11.Steel Res Int,2008,79(2):111 [1]Srivastava A,Joshi V,Shivpuri R.Computer modeling and [16]Wang H Q.The relationship between stress control and strain prediction of thermal fatigue cracking in die-casting tooling.Wear, control in the field of low cycle fatigue.J Mater Eng,1983(4):17 2004,256(1-2):38 (王海清.低周疲劳领域中应力控制与应变控制的关系.材料工 [2]Hawryluk M,Dolny A,Mrozinski S.Low cycle fatigue studies of 程,1983(4):17) WCLV steel (1.2344)used for forging tools to work at higher [17]Wang Y Q,Du WQ,Luo Y X.A mean plastic strain fatigue-creep temperatures.Arch Civil Mech Eng,2018,18(2):465 life prediction and reliability analysis of AISI H13 based on energy [3]Zuo P P,Wu X C.Zeng Y,et al.Strain-controlled thermal- method.J Mater Res,2017,32(22):4254 mechanical fatigue behavior of 4Cr5MoSiVl hot work die steel [18]Zeng Y,Zuo PP,Wu X C,et al.Effects of mechanical strain Chin J Eng,2018,40(1:76 amplitude on the isothermal fatigue behavior of H13.IntJMiner (左鹏鹏,吴晓春,曾艳,等.基于应变控制的4Cr5 MoSiV1热作模 Metall Mater,2017,24(9):1004 具钢热机械疲劳行为.工程科学学报,2018,40(1):76) [19]Wang M,Wu Y,Wei Q S,et al.Thermal fatigue properties of H13 [4]Salem M,Le Roux S,Dour G,et al.Effect of aluminizing and hot-work tool steels processed by selective laser melting.Metals, oxidation on the thermal fatigue damage of hot work tool steels for 2020,10(1):116试样,说明应变会加速疲劳过程中材料的软化;无 论有无应变幅,随着循环时间的增加,试样硬度都 会下降,也说明等温疲劳实验是循环软化的过程. 试样由表及里的硬度差值不大,可以反映出在疲 劳实验过程中疲劳试验机温差控制的较好,减小 了心表温差造成的硬度差值. 500 450 400 350 300 250 200 Microhardness, HV0.3 Distance from the surface/mm Δεm/2=0 (18.6 h) Δεm/2=0 (11.4 h) Δεm/2=0 (13.1 h) Δεm/2=0.7% (18.6 h) Δεm/2=1.1% (13.1 h) Δεm/2=0.9% (11.4 h) 0 0.5 1.0 1.5 2.0 2.5 3.0 图 9 等温疲劳试样显微硬度 Fig.9 Microhardness of isothermal fatigue specimen 3 结论 (1)H13 钢的 600 ℃ 等温疲劳实验中,在 0.7%、 0.9% 和 1.1% 三种不同应变幅下,应变幅越大,试 样疲劳寿命越短,1.1% 应变幅试样的寿命仅为 0.7% 应变幅的 61.2%. (2)应变促进裂纹扩展,1.1% 应变幅试样主裂 纹更明显、裂纹宽度更大、扩展长度更长;应变增 强氧化作用,应变幅越小,在高温下暴露时间越 长,氧化层覆盖情况越严重. (3)等温疲劳试样组织有长大和粗化,应变对 碳化物析出有助力作用,1.1% 应变幅试样碳化物 较 0.7% 应变幅试样平均直径小 8.5%,数量多 36.3%. 参 考 文 献 Srivastava A, Joshi V, Shivpuri R. Computer modeling and prediction of thermal fatigue cracking in die-casting tooling. Wear, 2004, 256(1-2): 38 [1] Hawryluk M, Dolny A, Mroziński S. Low cycle fatigue studies of WCLV steel (1.2344) used for forging tools to work at higher temperatures. Arch Civil Mech Eng, 2018, 18(2): 465 [2] Zuo P P, Wu X C, Zeng Y, et al. Strain-controlled thermalmechanical fatigue behavior of 4Cr5MoSiV1 hot work die steel. Chin J Eng, 2018, 40(1): 76 (左鹏鹏, 吴晓春, 曾艳, 等. 基于应变控制的4Cr5MoSiV1热作模 具钢热机械疲劳行为. 工程科学学报, 2018, 40(1):76) [3] Salem M, Le Roux S, Dour G, et al. Effect of aluminizing and oxidation on the thermal fatigue damage of hot work tool steels for [4] high pressure die casting applications. Int J Fatigue, 2019, 119: 126 Bombač D, Gintalas M, Kugler G, et al. Thermal fatigue behaviour of Fe-1.7C-11.3Cr-1.9Ni-1.2Mo roller steel in temperature range 500–700 ℃. Int J Fatigue, 2019, 121: 98 [5] Lu Y, Ripplinger K, Huang X J, et al. A new fatigue life model for thermally-induced cracking in H13 steel dies for die casting. J Mater Process Technol, 2019, 271: 444 [6] Liu B, Wang B, Yang X D, et al. Thermal fatigue evaluation of AISI H13 steels surface modified by gas nitriding with pre- and post-shot peening. Appl Surf Sci, 2019, 483: 45 [7] Ghusoon R M, Rawaa H M, Basim H A. Effect of die geometry on thermal fatigue of tool steel in aluminium alloy die-casting. IOP Conf Ser Mater Sci Eng, 2019, 518(3): 032042 [8] Girisha V A, Joshi M M, Kirthan L J, et al. Thermal fatigue analysis of H13 steel die adopted in pressure-die-casting process. Sādhanā, 2019, 44: 148 [9] Meng C, Wu C, Wang X L, et al. Effect of thermal fatigue on microstructure and mechanical properties of H13 tool steel processed by selective laser surface melting. Metals, 2019, 9(7): 773 [10] Wu X C, Xu L P. Quantitative analysis and evaluation of the Uddeholm heat-checking scale. Phys Test Chem Anal Part A, 2002, 38(1): 14 (吴晓春, 许珞萍. Uddeholm热疲劳图谱的分析与定量评定. 理 化检验–物理分册, 2002, 38(1):14) [11] Ma Y, Wang H, Chai X, et al. Thermal fatigue behavior of HHD hot work tool steel with structures. Mater Sci Eng Technol, 2018, 49(12): 1494 [12] Zuo P P, Wu X C, Zeng Y, et al. In-phase and out-of-phase thermomechanical fatigue behavior of 4Cr5MoSiV1 hot work die steel cycling from 400 ℃ to 700 ℃. Fatigue Fract Eng Mater Struct, 2018, 41(1): 159 [13] Grüning A, Lebsanft M, Scholtes B. Isothermal and thermal fatigue of tool steel AISI H11. Mater Sci Forum, 2010, 638-642: 3230 [14] Grüning A, Krauβ M, Scholtes B. Isothermal fatigue of tool steel AISI H11. Steel Res Int, 2008, 79(2): 111 [15] Wang H Q. The relationship between stress control and strain control in the field of low cycle fatigue. J Mater Eng, 1983(4): 17 (王海清. 低周疲劳领域中应力控制与应变控制的关系. 材料工 程, 1983(4):17) [16] Wang Y Q, Du W Q, Luo Y X. A mean plastic strain fatigue-creep life prediction and reliability analysis of AISI H13 based on energy method. J Mater Res, 2017, 32(22): 4254 [17] Zeng Y, Zuo P P, Wu X C, et al. Effects of mechanical strain amplitude on the isothermal fatigue behavior of H13. Int J Miner Metall Mater, 2017, 24(9): 1004 [18] Wang M, Wu Y, Wei Q S, et al. Thermal fatigue properties of H13 hot-work tool steels processed by selective laser melting. Metals, 2020, 10(1): 116 [19] 朱振强等: 应变幅对 H13 热作模具钢等温疲劳行为的影响 · 661 ·