【摘要】：高強鋼在現(xiàn)實熱沖壓過程中,因為某些未知原因有時也會呈現(xiàn)出缺陷。唐鋼在供給客戶的汽車高強鋼在沖壓過程中也出現(xiàn)了一些缺陷。產(chǎn)生此問題的原因是高強鋼本身合格與否還是熱沖壓加工工藝存在問題,目前還無法確定。在高強鋼的熱沖壓成型過程建立有限元模擬和實驗研究,能夠探究熱沖壓缺陷產(chǎn)生原因,使沖壓工藝得以優(yōu)化,對分析高強度鋼熱沖壓成型過程具有十分重要的作用。首先構(gòu)建出了適用于板厚1.3~2.16 mm的U形汽車沖壓件簡化模型。以唐鋼生產(chǎn)的22MnB5汽車用高強鋼為研究對象,通過高溫拉伸實驗以及整理一些相關(guān)數(shù)據(jù)構(gòu)建了熱沖壓成型所需要的材料性能數(shù)據(jù)庫,建立了熱沖壓成型的有限元分析模型,設(shè)計制作了沖壓模具,并進行了相關(guān)的沖壓實驗,檢測了成型零件的成型質(zhì)量。成型過程中的應(yīng)力和溫度的變化規(guī)律存在共性,最初選定的板材開始沖壓的初始溫度為850℃,模具溫度為20℃,沖壓速度為40 mm/s。板料與模具之間的摩擦系數(shù)設(shè)為0.2,傳熱系數(shù)為50 N/(s·mm·℃)。隨著變形過程的進行鋼板溫度逐漸降低,并且在接觸的區(qū)域降溫較快。鋼板應(yīng)力隨著熱沖壓變形過程的進行逐漸增大,凸模、凹模圓角附近應(yīng)力值一直比較高。經(jīng)過研究沖壓成型的影響因素,包括模具和板料間的摩擦系數(shù)、板料的初始溫度、模具的初始溫度和沖壓速度等工藝參數(shù)的影響,通過對比得到最佳的熱沖壓成型工藝參數(shù):板料的初始溫度為900℃,沖壓速度為50 mm/s,摩擦系數(shù)為0.1。測得成型后零件的強度與軋制態(tài)相比得到了大幅提升,屈服強度、抗拉強度和延伸率指標均滿足要求。按照此工藝對1.4 mm厚的22MnB5鋼板進行熱沖壓是十分符合生產(chǎn)需求的,可以作為生產(chǎn)實踐的理論指導(dǎo)。
[Abstract]:In the process of hot stamping, high-strength steel sometimes shows defects because of some unknown reasons. Tangshan Iron and Steel in the supply of automotive high-strength steel customers in the stamping process also appeared some defects. The reason for this problem is whether the high strength steel itself is qualified or the hot stamping process. The finite element simulation and experimental study on the hot stamping process of high strength steel can explore the causes of hot stamping defects and optimize the stamping process, which plays an important role in the analysis of hot stamping process of high strength steel. Firstly, a simplified model of U-shaped automobile stamping parts suitable for plate thickness of 1. 3 ~ 2. 16 mm was constructed. Taking the high-strength steel for 22MnB5 automobile produced by Tangshan Iron and Steel Co. Ltd as the research object, the material performance database for hot stamping forming was constructed by high temperature tensile test and some related data, and the finite element analysis model of hot stamping forming was established. The stamping die is designed and manufactured, and the relevant stamping experiments are carried out to test the forming quality of the forming parts. The variation of stress and temperature in the forming process has a common character. The initial temperature of the first selected sheet metal is 850 鈩，

本文編號：2402486