摘要
基于30Cr2Ni4MoV钢的TTT转变曲线,研究了不同珠光体转变量对30Cr2NiMoV钢100~500℃之间的高温拉伸性能和调质后晶粒度的影响规律,并采用Deform-HT模拟了不同直径的30Cr2Ni4MoV低压转子采用等温热处理工艺时的应力,通过对比高温拉伸性能,确定其应力风险。结果表明,珠光体转变量在40%以下时,断口形貌为沿晶断口和韧窝断口,沿晶断口出现在粗晶位置;珠光体转变量大于40%时,断口形貌为韧窝断口。通过调质时的奥氏体自发再结晶和15%以上珠光体转变量相结合的方式,可以通过1次奥氏体化加调质的方式使晶粒细化和均匀化,大幅度缩短热处理工艺周期。不同直径的低压转子采用等温热处理工艺时,应力风险很低。
On the basis of the TTT transition curve of 30Cr2Ni4MoV steel,this paper introduces the research on the influence and the regularity of transition quantity of various pearlite to tensile property of 30Cr2NiMoV steel at high temperature of 100 ~ 500℃ and its grain size after quenching and tempering, and simulates the stresses of 30Cr2Ni4MoV low pressure rotor with different diameters by Deform-HT in the way of isothermal heat treatment process,identifies the risk of stress by contrasting the high temperature tensile property. The result shows that when the tranisition quantity of pearlite is lower than 40%,the fractures morphology are intergranular fracture and dimple fracture,the intergranular fracture appears at coarse grain＇ s,and when the transition quantity of pearlite is more than40%,the fracture morphology is just dimple fracture. By combining the spontaneous recrystallization of austenite at the time of quenching and tempering and more than 15% pearlite transition quantity,the grain can be refined and homogenized by one austenitizing,quenching and tempering,which significantly shorten the period of heat treatment. The risk of stress is low when the low pressure rotors with different diameters are treated by isothermal heat treatment process.
出处
《大型铸锻件》
2017年第6期25-29,37,共6页
Heavy Casting and Forging
