發(fā)布時間：2018-05-22 14:24

  本文選題：中碳鋼 + 晶粒細化��； 參考：《華北理工大學(xué)》2017年碩士論文

【摘要】：通過對不同初始組織中碳鋼和工業(yè)純鐵進行不同軋制道次的溫軋及退火試驗,研究了不同塑性變形工藝對鐵基合金組織和性能的影響規(guī)律。溫軋過程中,鐵素體發(fā)生動態(tài)回復(fù)與再結(jié)晶,晶粒尺寸隨軋制道次增加而減小。8道次溫軋,工業(yè)純鐵的平均晶粒尺寸為5.11μm,馬氏體鋼和偽共析鋼的晶粒尺寸分別減小至0.77μm和0.52μm。由拉伸試驗可得,8道次溫軋后,工業(yè)純鐵的強度和塑性均較低,馬氏體鋼的屈服強度雖較高,但延伸率較低,且無均勻變形階段;只有偽共析鋼的綜合性能得到明顯改善,8道次溫軋的屈服強度和均勻延伸率分別為1167.0MPa和6.2%,表現(xiàn)出相當(dāng)?shù)木鶆蜃冃文芰Α?道次溫軋后,對馬氏體鋼和偽共析鋼進行后續(xù)600℃退火處理。馬氏體鋼組織具有較強的熱穩(wěn)定性,晶粒尺寸隨退火時間延長增大幅度較小。偽共析鋼退火時,鐵素體晶粒尺寸呈雙峰分布。對軋后退火試樣進行拉伸試驗,試驗材料的強度隨退火時間的延長而逐漸降低。相同保溫時間內(nèi),偽共析鋼的屈服強度和馬氏體鋼接近,但均勻延伸率明顯高于馬氏體鋼,因而顯示出更好的強韌性,均勻變形能力更強。實驗結(jié)果表明,與相同工藝下其他試驗材料相比,偽共析鋼溫軋及退火后的強韌性顯著提升,這主要是由于偽共析鋼在溫軋和退火處理后,顯微組織呈多尺度晶粒帶狀分布或晶粒尺寸雙峰分布,因而能夠在變形過程中引起應(yīng)變梯度效應(yīng),誘發(fā)幾何必須位錯的產(chǎn)生,使加工硬化能力增強,綜合性能提升。
[Abstract]:The effects of different plastic deformation processes on the microstructure and properties of Fe-base alloys were studied by warm rolling and annealing tests of carbon steel and industrial pure iron with different initial microstructure. Dynamic recovery and recrystallization of ferrite occurred during warm rolling. The grain size decreased with the increase of rolling pass. The average grain size of industrial pure iron was 5.11 渭 m, and the grain size of martensite steel and pseudoeutectoid steel decreased to 0.77 渭 m and 0.52 渭 m, respectively. The tensile test shows that the strength and plasticity of industrial pure iron are lower after 8 passes of warm rolling. The yield strength of martensitic steel is higher, but the elongation is lower, and there is no uniform deformation stage. Only the comprehensive properties of pseudoeutectoid steel were improved obviously, the yield strength and uniform elongation of 8 pass warm rolling were 1167.0MPa and 6.2, respectively, showing a considerable uniform deformation ability after 8 pass warm rolling. Martensitic steel and pseudoeutectoid steel were annealed at 600 鈩，

本文編號：1922451