通化硕抠家具有限公司

    P91耐熱鋼熱變形行為及其流變應(yīng)力本構(gòu)方程

    Hot Deformation Behavior of P91 Heat-resistant Steel and Related Flow Stress Constitutive Equations

    • 摘要: 基于位錯反應(yīng)理論和Avrami方程,建立了包含動態(tài)應(yīng)變時效影響的動態(tài)回復(fù)與動態(tài)再結(jié)晶的兩階段本構(gòu)方程。采用Gleeble3500熱模擬試驗(yàn)機(jī)對P91耐熱鋼進(jìn)行熱壓縮試驗(yàn),獲得了950~1200℃、0.01~10s-1條件下的P91耐熱鋼真應(yīng)力-真應(yīng)變曲線。利用試驗(yàn)獲得的流變應(yīng)力數(shù)據(jù),采用非線性擬合確定了P91鋼本構(gòu)方程中的材料常數(shù)。模型的計算結(jié)果表明,計算曲線與試驗(yàn)曲線吻合得較好,所建立的本構(gòu)方程可應(yīng)用于預(yù)測P91鋼在950~1200℃、0.01~10s-1條件下熱加工變形的流變應(yīng)力。

       

      Abstract: Based on the dislocation reaction theory and the Avrami equation,a two-stage constitutive equation model is developed to describe dynamic recovery and dynamic re-crystallization,which couple the effect of the dynamic strain aging in the alloy during hot deformation. With the Gleeble 3500 simulation testing machine,uniaxial thermocompression tests to the P91 heat resistant steel are carried out under the conditions of 950~1 200 ℃ and 0.01~10 s-1,which results in the true stress-true strain curves thereof. In combination with the experimental data concerning the flow stress of the P91 steel,the material parameters of the said constitutive equation are determined by using the non-linear dada-fitting method. The calculation result from the constitutive equation shows that the calculated curves are in compliance with the experimental curves,which means that the constitutive equation of the P91 steel is capable of predicting the flow stresses of the steel being deformed at the hot working conditions of temperature ranging from 950 ℃ to 1 200 ℃,and strain rating from 0.01 s-1 to 10 s-1.

       

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