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51Cr V4钢因具有良好的热处理性能与力学性能,广泛用作为高等级弹簧钢。为改善现有锯片钢的不足,根据51Cr V4特有的化学成分,创新性地将其用于制造金刚石焊接锯片基体。通过研究动态CCT曲线,卷取温度对显微组织与第二相析出物的影响,淬火与回火工艺对碳化物尺寸、晶粒尺寸、力学性能的影响,评估了51Cr V4钢用于制造金刚石焊接锯片基体的可行性。结果表明:卷取温度升高,先共析铁素体尺寸与珠光体片层间距变大,10 nm粒径以下的(V,Cr)C析出物在MC相析出物中所占的比例减少;淬火温度由800提高到900℃时,奥氏体晶粒尺寸先缓慢变化,随后快速长大,固溶的碳化物质量分数增多,回火后锯片硬度增强,而回火温度由450提高到550℃时,马氏体板条界片层状渗碳体逐步球化,强度明显下降,塑性小幅提高;设定合适的卷取温度控制热轧态中第二相碳化物的尺寸,并在850~900℃淬火、约450℃回火是生产高硬度、高韧性51Cr V4金刚石焊接锯片的关键工艺。
51Cr V4 steel is widely used as high grade spring steel because of its good heat treatment and mechanical properties. In order to improve the shortcomings of the existing saw blade steel, it is innovatively used for manufacturing a diamond saw blade base substrate according to the unique chemical composition of 51Cr V4. The effects of dynamic CCT curve, coiling temperature on microstructure and second phase precipitates, quenching and tempering process on carbide size, grain size, and mechanical properties were evaluated. The effects of 51Cr V4 steel on diamond Feasibility of welding blade substrate. The results show that when the coiling temperature is increased, the segregation of proeutectoid ferrite and pearlite layer becomes larger, and the proportion of (V, Cr) C precipitates below the particle size of 10 nm in MC precipitates decreases ; When the quenching temperature is increased from 800 to 900 ℃, the austenite grain size slowly changes first and then rapidly grows, the solid solution carbides mass fraction increases, the hardness of the saw blade increases after tempering, and the tempering temperature increases from 450 At 550 ℃, the lamellar cementite in the martensite lamellae gradually spheroidized, the strength decreased obviously and the plasticity increased slightly. The suitable coiling temperature was used to control the size of the second-phase carbides in the hot-rolled state Quenching at 850 ~ 900 ℃, tempering at about 450 ℃ is the key process for the production of high hardness, high toughness 51Cr V4 diamond welding saw blade.