Transactions of Materials and Heat Treatment

Title：Influence of pre-strain on formability of dual-phase steel material for automobile

Authors：

Unit：

KeyWords：

ClassificationCode：TF76; TG142.1

year,vol(issue):pagenumber：2020,45(11):181-186

Abstract：

The phase transformation of dual-phase steel is complicated during the forming process, and the error in evaluating its formability by ordinary tensile properties alone is relatively large. Therefore, for DP780 dual-phase steel, according to the actual production parameters and experimental conditions, different pre-strains (0%, 5%, 10% and 15%) were applied to uniaxial tensile samples, and the tensile tests were conducted until the samples broke. Then, the mechanical properties and work hardening of materials after pre-stretching were evaluated. The results show that DP780 dual-phase steel has the characteristics of good tensile strength, high work hardening index and low yield ratio, but the plasticity is low, and the elongation is only 20.7%. With the increasing of pre-strain, both yield strength and tensile strength increase correspondingly, but the change of tensile strength is small, and the pre-strain mainly affects the elongation of DP780 dual-phase steel. After the pre-stretched sample continues to be stretched, the value of work hardening index n decreases to the minimum value at the beginning of stretch. With the stretch continues, the n value slowly increases, which is obviously different from that of the tensile specimen without pre-stretching. Furthermore, the work hardening of DP780 dual-phase steel after pre-strain is mainly manifested in the large strain area.

Funds：

教育部产学协同育人项目（201802048105）

乔书杰（1983-），女，硕士，讲师 E-mail：njlgdxhjy@163.com

Reference：

[1]郭玉琴, 王帅, 朱新峰,等. 双相钢温拉伸的后继屈服行为[J]. 塑性工程学报, 2015, 22(4):141-145.

Guo Y Q, Wang S, Zhu X F, et al. Study on the subsequent yield behaviors of DP steel under warm tension[J]. Journal of Plasticity Engineering, 2015, 22(4):141-145.

[2]陈红兵, 刘天模, 卢立伟, 等. 预应变和热处理对AZ31镁合金形变行为的影响[J]. 中国有色金属学报：英文版, 2015(11):3604-3610.

Chen H B, Liu T M, Lu L W, et al. Influence of pre-strain and heat treatment on subsequent deformation behavior of extruded AZ31 Mg alloy [J]. Transactions of Nonferrous Metals Society of China, 2015，(11):3604-3610.

[3]GB/T 228.1—2010，金属材料拉伸试验第1部分：室温试验方法[S].

GB/T 228.1—2010，Metallic Materials—Tensile testing—Part 1:Method of test at room temperature[S].

[4]王敏莉. 预应变与烘烤工艺对780 MPa级冷轧双相钢组织性能的影响[J]. 钢铁钒钛, 2017，(5):135-141.

Wang M L. Effects of pre-strain and baking process on the microstructure and bake-hardening behavior of 780 MPa cold rolled dual-phase steel[J]. Iron Steel Vanadium Titanium, 2017，(5):135-141.

[5]徐欢欢, 张志清, 吴赛楠, 等. 预应变和预时效对Al-Mg-Si合金烘烤硬化性能的影响[J]. 中国有色金属学报, 2013，(3):623-627.

Xu H H, Zhang Z Q, Wu S N, et al. Effect of pre-straining and pre-ageing on bake hardening response of Al-Mg-Si alloy [J]. The Chinese Journal of Nonferrous Metals, 2013，(3):623-627.

[6]张睿, 邓宇君, 易培云, 等. 预应变超薄不锈钢板材弯曲回弹[J]. 塑性工程学报, 2018, 25(6):20-26.

Zhang R, Deng Y J, Yi P Y, et al. Springback of pre-strain ultrathin stainless steel sheet [J]. Journal of Plasticity Engineering, 2018, 25(6):20-26.

[7]聂丽丽, 李维娟, 王喆, 等. 预应变对超低碳烘烤硬化钢烘烤硬化性能的影响[J]. 热加工工艺, 2013，(24):121-123.

Nie L L, Li W J, Wang Z, et al. Effect of pre-strain on bake hardening properties of ultra-low carbon bake hardening steel [J]. Hot Working Technology, 2013，(24):121-123.

[8]胡汉江, 赵爱民, 印珠凯, 等. 预应变对TRIP钢力学性能及硬化行为的影响[J]. 材料热处理学报, 2016，37(5):128-132.

Hu H J, Zhao A M, Yin Z K, et al. Effect of pre-strain on mechanical properties and hardening behavior of TRIP steel [J]. Transactions of Materials and Heat Treatment, 2016，37(5):128-132.

[9]赵征志, 叶洁云, 汪志刚, 等. 高强度冷轧双相钢应变硬化行为[J]. 沈阳工业大学学报, 2013, 35(1):36-40.

Zhao Z Z, Ye J Y, Wang Z G, et al. Strain hardening behavior of high strength cold rolled duplex steel[J]. Journal of Shenyang University of Technology, 2013, 35(1):36-40.

[10]胡德伟, 陈劼实, 胡晓, 等. 预应变对铝合金板冲裁断面质量的影响[J]. 锻压技术, 2018，43(4):47-52.

Hu D W, Chen J S, Hu X, et al. Influence of pre-strain on quality of blanking cross section for aluminum alloy sheet [J]. Forging & Stamping Technology, 2018， 43(4):47-52.

[11]Bandyopadhyay K, Basak S, Panda S K, et al. Use of stress based forming limit diagram to predict formability in two-stage forming of tailor welded blanks [J]. Materials & Design, 2015, 67:558-570.

[12]肖光春, 荆洪阳, 徐连勇. 预应变对高强结构钢低温断裂韧性的影响[J]. 天津大学学报：自然科学与工程技术版, 2011, 44(4):303-307.

Xiao G C, Jing H Y, Xu L Y. Effect of prestrain on fracture toughness of high-strength structural steel at low temperature[J]. Journal of Tianjin University：Science and Technology, 2011, 44(4):303-307.

[13]毛博文, 孙晓屿, 王武荣, 等. 预应变和应变速率对HC340LA低合金高强钢力学性能的影响[J]. 塑性工程学报, 2014, 21(1):7-12.

Mao B W, Sun X Y, Wang W R, et al. Effect of pre-strain and strain rates on mechanical properties of HC340LA high strength low alloy steel [J]. Journal of Plasticity Engineering, 2014, 21(1):7-12.

Service：

【This site has not yet opened Download Service】【Add Favorite】