【摘要】 通过建立超高压射流超快冷却传热物理模拟平台，测定了28CrMoVNiRE钢油井管在不同水雾、水压和喷嘴高度冷却条件下的冷却曲线，利用反传热法计算试样表面热流密度及换热系数，研究无缝钢管超高压射流超快冷却传热机理，并通过有限元模拟验证了反传热计算的准确性。为探究超高压射流超快冷却对无缝钢管组织性能的影响，分别对钢管原始热轧态和不同超快冷却条件下的钢管试样进行了微观组织分析以及力学性能测试。结果表明，在喷嘴高度为100 mm时，水压由6 MPa提升至7 MPa,平均换热系数由386.0 W/(m~2·℃)提升至859.1 W/(m~2·℃),平均热流密度由0.15 MW/m~2提升至0.35 MW/m~2。当水压为7 MPa,喷嘴高度由100 mm增加到160 mm时，平均冷却速度提高6.2%;换热系数随温差ΔT的下降先后经历两个阶段：高温、中温近线性快速增长阶段和低温快速下降阶段。试验钢在喷淋水压7 MPa,喷嘴高度160 mm的冷却条件下，马氏体板条宽度能够平均细化至0.35μm,与原始热轧态钢相比硬度和冲击吸收能量均提升，验证了超高压射流超快冷却技术具有可行性。更多还原

【Abstract】 Cooling curves of 28CrMoVNiRE steel oil well tube under different water mists, water pressures and nozzle height cooling conditions were measured by establishing a physical simulation platform of ultra-high pressure jet ultra-fast cooling heat transfer. The heat flux density and heat transfer coefficient of the specimen surface were calculated by inverse heat transfer method. The heat transfer mechanism of ultra-high pressure jet ultra-fast cooling of seamless steel tube was studied, and the accuracy of inverse heat transfer calculation was verified by finite element simulation. In order to explore the effect of ultra-high pressure jet ultra-fast cooling on the microstructure and properties of seamless steel tubes, the microstructure analysis and mechanical properties tests of the steel tube under original hot-rolling state and different ultra-fast cooling conditions were carried out respectively. The results show that when the nozzle height is 100 mm, the water pressure increases from 6 MPa to 7 MPa, the average heat transfer coefficient increases from 386.0 W/(m~2·℃) to 859.1 W/(m~2·℃), and the average heat flux density increases from 0.15 MW/m~2 to 0.35 MW/m~2. When the water pressure is 7 MPa and the nozzle height increases from 100 mm to 160 mm, the average cooling rate increases by 6.2%. The heat transfer coefficient with the decrease of temperature difference ΔT goes through two stages: high temperature, medium temperature near linear rapid growth stage and low temperature rapid decline stage. It is found that the martensite lath width of the tested steel can be refined to 0.35 μm on average under the cooling conditions of spray water pressure of 7 MPa and nozzle height of 160 mm. Compared with the original hot-rolled steel, the hardness and the impact absorbed energy increase, which verifies the feasibility of ultra-high pressure jet ultra-fast cooling technology.更多还原