轧制差厚板预成形工艺对Al-Si镀层的影响

doi:10.12068/j.issn.1005-3026.2025.20240044

摘要/Abstract

摘要：

间接热成形工艺在热冲压前需要对原料进行预成形，轧制差厚板在变厚度轧制后加工硬化程度不同，预成形前需要进行退火处理.针对Al-Si镀层差厚板的预成形工艺进行了研究，结果表明，经过600~620 ℃退火后，延伸率提升至16.0%~26.2%.镀层总体厚度变化不大，镀层结构由从外到内的Al基、合金扩散层、Fe₂Al₅+FeAl₃的三层结构演变为τ₅-Fe₂SiAl₇、含τ₁-Fe₃Al₂Si₃的薄带状组织、η-Fe₂Al₅、η-Fe₂Al₅和基体之间一层1~2 μm的合金化合物组成的4层结构.随着退火温度升高，含τ₁-Fe₃Al₂Si₃的带状区域由τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+θ-FeAl₃转变为τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+η-Fe₂Al₅；随着时间增加，该区域由τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+θ-FeAl₃转变为τ₁-Fe₃Al₂Si₃+θ-FeAl₃+η-Fe₂Al₅.10%，30%压下率的镀层分层结构相同，从外到内分别为τ₅-Fe₂SiAl₇，τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+θ-FeAl₃，η-Fe₂Al₅；而50%压下率时则为τ₅-Fe₂SiAl₇，τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+η-Fe₂Al₅，η-Fe₂Al₅.

关键词: 轧制差厚板, 预成形, Al-Si镀层, 退火, 力学性能

Abstract:

Indirect hot forming process needs to preform raw materials before hot stamping. Tailor rolled blanks （TRBs）have different work hardening degrees after variable thickness rolling， so annealing treatment is needed before preforming. The preforming process of Al-Si coated TRB was studied. The results show that the elongation increases to 16.0%~26.2% after annealing at 600~620 ℃. The total thickness of the coating has little change， and its structure changes from the three-layer structure consisting of Al base， alloy diffusion layer and Fe₂Al₅+FeAl₃ （from outer to inner） into a four-layer structure comprising τ₅-Fe₂SiAl₇， thin band structure containing τ₁-Fe₃Al₂Si₃， η-Fe₂Al₅， and alloy compound with a layer of 1~2 μm between η-Fe₂Al₅ and substrate. With increasing annealing temperature， the ribbon region containing τ₁-Fe₃Al₂Si₃ changes from τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+θ-FeAl₃ to τ₁-Fe₃Al₂Si₃+θ-FeAl₃+η-Fe₂Al₅， and with increasing annealing time， the region changes from τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+θ-FeAl₃ to τ₁-Fe₃Al₂Si₃+θ-FeAl₃+η-Fe₂Al₅. The layered structures of the coatings with 10% and 30% reduction ratios are the same， τ₅-Fe₂SiAl₇， τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+θ-FeAl₃ and η-Fe₂Al₅ from outer to inner. When the reduction ratio is 50%， the layered structure consists of τ₅-Fe₂SiAl₇， τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+η-Fe₂Al₅ and η-Fe₂Al₅ from outer to inner.

Key words: tailor rolled blank（TRB）, pre-forming, Al-Si coating, annealing, mechanical property

中图分类号:

TF 046

胡贤磊, 韩鹏, 解勤诚, 支颖. 轧制差厚板预成形工艺对Al-Si镀层的影响[J]. 东北大学学报（自然科学版）, 2025, 46(9): 65-72.

Xian-lei HU, Peng HAN, Qin-cheng XIE, Ying ZHI. Effect of Pre-forming Process of Tailor Rolled Blank on Al-Si Coating[J]. Journal of Northeastern University(Natural Science), 2025, 46(9): 65-72.

图/表 13

表1 22MnB5钢化学成分（质量分数） (%)

Table 1 Chemical composition of 22MnB5 steel(mass fraction)

C	Si	Mn	P	S	Ti	Cr	V	B	Fe
0.214	0.226	1.142	0.011	0.002	0.039	0.173	0.003	0.003	余量

图1 实验工艺路径

Fig.1 Experimental process path

图2 拉伸试样尺寸

Fig.2 Dimensions of tensile specimens

图3 不同压下率Al-Si镀层形貌（a）—0；（b）—10%；（c）—30%；（d）—50%.

Fig.3 Morphology of Al-Si coating with different reduction ratios

图4 不同压下率拉伸性能

Fig.4 Tensile properties with different reduction ratios

图5 Al-Si镀层SEM、元素线扫描、面扫描图（a）—600 ℃；（b）—620 ℃.

Fig.5 SEM, element line scan and surface scan of Al-Si coating

表2 退火态Al-Si镀层中元素成分及物相（原子分数） (%)

Table 2 Element content and phases of annealed Al-Si coating (atomic fraction)

检测点	Al	Si	Fe	物相
A₁	66.80	10.50	22.71	τ₅-Fe₂SiAl₇
A₂	48.80	18.26	32.94	τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+θ-FeAl₃
A₃	71.57	0.75	27.69	η-Fe₂Al₅
B₁	62.94	8.02	29.04	τ₅-Fe₂SiAl₇
B₂	50.55	21.83	27.62	τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+η-Fe₂Al₅
B₃	68.81	1.82	29.37	η-Fe₂Al₅

图6 Al-Si镀层SEM、元素线扫描、面扫描图（a）—1 h；（b）—4 h.

Fig.6 SEM, element line scan and surface scan of Al-Si coating

表3 退火态Al-Si镀层中元素成分及物相（原子分数） (%)

Table 3 Element content and phases of annealed Al-Si coating(atomic fraction)

检测点	Al	Si	Fe	物相
C₁	68.29	9.30	22.41	τ₅-Fe₂SiAl₇
C₂	61.62	18.56	19.82	τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+θ-FeAl₃
C₃	72.40	0.77	26.83	θ-FeAl₃
C₄	68.85	1.71	29.44	η-Fe₂Al₅
D₁	71.97	5.49	22.54	η-Fe₂Al₅
D₂	41.54	24.09	34.36	τ₁-Fe₃Al₂Si₃+θ-FeAl₃+η-Fe₂Al₅
D₃	69.46	1.49	29.05	η-Fe₂Al₅

图7 Al-Si镀层SEM、元素线扫描、面扫描图（a）—10%；（b）—50%.

Fig.7 SEM, element line scan and surface scan of Al-Si coating

表4 退火态Al-Si镀层中元素成分及物相（原子分数） (%)

Table 4 Element content and phases of annealed Al-Si coating（atomic fraction）

检测点	Al	Si	Fe	物相
E₁	69.60	9.79	20.61	τ₅-Fe₂SiAl₇
E₂	55.48	13.17	31.35	τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+θ-FeAl₃
E₃	70.73	1.36	27.91	η-Fe₂Al₅
F₁	65.35	10.28	24.37	τ₅-Fe₂SiAl₇
F₂	56.41	21.46	22.13	τ₁-Fe₃Al₂Si₃+τ₂-FeAl₃Si+η-Fe₂Al₅
F₃	69.69	1.09	29.22	η-Fe₂Al₅

图8 XRD结果

Fig.8 XRD results

表5 不同退火工艺的拉伸性能 (processes)

Table 5 Tensile properties of different annealing

工艺参数	$抗拉强度 M P a$	$屈服强度 M P a$	$延伸率 %$
10%-600 ℃-2 h	590	512	22.1
30%-600 ℃-1 h	615	528	15.3
30%-600 ℃-2 h	601	505	16.4
30%-620 ℃-2 h	587	490	17.8
30%-600 ℃-4 h	568	446	18.2
50%-600 ℃-2 h	474	348	26.2

表5 不同退火工艺的拉伸性能 (processes)

Table 5 Tensile properties of different annealing

工艺参数	$抗拉强度 M P a$	$屈服强度 M P a$	$延伸率 %$
10%-600 ℃-2 h	590	512	22.1
30%-600 ℃-1 h	615	528	15.3
30%-600 ℃-2 h	601	505	16.4
30%-620 ℃-2 h	587	490	17.8
30%-600 ℃-4 h	568	446	18.2
50%-600 ℃-2 h	474	348	26.2

参考文献 24

[1]	Karbasian H， Tekkaya A E.A review on hot stamping［J］.Journal of Materials Processing Technology， 2010，210（15）：2103-2118.
[2]	Taub A， de Moor E， Luo A L，et al.Materials for automotive lightweighting［J］.Annual Review of Materials Research，2019，49：327-359.
[3]	Kiani M， Gandikota I， Rais-Rohani M，et al.Design of lightweight magnesium car body structure under crash and vibration constraints［J］. Journal of Magnesium and Alloys，2014，2（2）：99-108.
[4]	Fan D W， de Cooman B C.State-of-the-knowledge on coating systems for hot stamped parts［J］.Steel Research International，2012，83（5）：412-433.
[5]	Yooa J， Kimb S， Jo M C，et al.Effects of Al-Si coating structures on bendability and resistance to hydrogen embrittlement in 1.5 GPa-grade hot-press-forming steel［J］.Acta Materialia，2022，225：1-18.
[6]	Windmann M， Röttger A， Theisen W.Formation of intermetallic phases in Al-coated hot-stamped 22MnB5 sheets in terms of coating thickness and Si content［J］.Surface and Coatings Technology，2014，246：17-25.
[7]	Klassen C M， Smith R D L， Daun K J. Characterizing the Al-Si coating on 22MnB5 steel using Raman spectroscopy［J］.Materials Characterization，2022，189：1-8.
[8]	Guan M， Wang Y， Liu Y X，et al.Optimizing bendability of AlSi-coated 2GPa-grade press-hardened steel by double austenitization［J］.Scripta Materialia，2023，235：1-7.
[9]	Lin W H， Li F， Wu D S，et al.Effect of Al-Si coating on weld microstructure and properties of 22MnB5 steel joints for hot stamping［J］.Journal of Materials Engineering and Performance，2018，27（4）：1825-1836.
[10]	Jo K R， Cho L， Sulistiyo D H，et al.Effects of Al-Si coating and Zn coating on the hydrogen uptake and embrittlement of ultra-high strength press-hardened steel［J］.Surface and Coatings Technology，2019，374： 1108-1119.
[11]	Kopp R.Some current development trends in metal-forming technology［J］.Journal of Materials Processing Technology，1996，60（1）：1-9.
[12]	Abratis C， Hirt G， Kopp R.Air bending process for load optimised profiles［J］.Steel Research International，2006，77（9/10）：754-759.
[13]	Merklein M， Johannes M， Lechner M，et al.A review on tailored blanks：production，applications and evaluation［J］.Journal of Materials Processing Technology，2014，214（2）：151-164.
[14]	Zhang H L， Sun G Y， Xiao Z，et al.Bending characteristics of top-hat structures through tailor rolled blank（TRB）process［J］.Thin-Walled Structures，2018，123：420-440.
[15]	Habibi M， Hashemi R， Fallah Tafti M，et al.Experimental investigation of mechanical properties，formability and forming limit diagrams for tailor-welded blanks produced by friction stir welding［J］.Journal of Manufacturing Processes，2018，31：310-323.
[16]	Seo H Y， Jin C K， Kang C G.Effect on blank holding force on blank deformation at direct and indirect hot deep drawings of boron steel sheets［J］.Metals，2018，8（8）：574.
[17]	Zhang S J， Hu X L， Niu C L，et al.Annealing of HC340LA tailor rolled blanks-control of mechanical properties and formability［J］.Journal of Materials Processing Technology，2020，281：1-13.
[18]	Yun S M， Gwon H， Oh J，et al.Suppression of coating layer crack by diffusion heat treatment in Al-Si coated HPF steels［J］.Metals and Materials International，2022，28（11）：2668-2676.
[19]	余伟，孙广杰，张飞.冷轧TRB薄板的连续退火工艺试验研究［J］.北京工业大学学报，2015，41（2）：293-298.
	Yu Wei， Sun Guang-jie， Zhang Fei.Experimental study of continuous annealing process for cold rolled TRB sheet［J］Journal of Beijing University of Technology，2015，41（2）：293-298.
[20]	徐文婷，余伟，孙广杰.22MnB5热成形钢变厚度轧制及退火工艺［J］.金属热处理，2015，40（11）：140-144.
	Xu Wen-ting， Yu Wei， Sun Guang-jie.Variable gauge rolling and annealing process of 22MnB5 hot stamping steel［J］.Heat Treatment of Metals，2015，40（11）：140-144.
[21]	Kim H W， Lim C Y.Annealing of flexible-rolled Al-5.5% Mg alloy sheets for auto body application［J］.Materials & Design，2010，31：S71-S75.
[22]	Cui G B， Meng Y， Ju X H，et al.Microstructure characterization of Al-Si coatings on hot stamping steel under different heat treatment processes［J］.ISIJ International，2023，63（4）：719-726.
[23]	Liu Z K， Chang Y A.Thermodynamic assessment of the Al-Fe-Si system［J］.Metallurgical and Materials Transactions A，1999，30（4）：1081-1095.
[24]	Raghavan V.Al-Fe-Si（aluminum-iron-silicon）［J］.Journal of Phase Equilibria and Diffusion，2012，33（4）：322-326.