锻造加热温度对20Cr2Ni4A钢奥氏体晶粒长大及力学性能的影响

研究了锻造加热温度(1050~1200 ℃)和锻造保温时间(40~120 min)对20Cr2Ni4A钢经相同锻造变形后锻后奥氏体晶粒长大行为的影响,并对不同锻造加热温度下的淬火态20Cr2Ni4A钢进行了力学性能检测。结果表明,锻后20Cr2Ni4A钢奥氏体晶粒长大规律在低于1150 ℃仍然符合Beck模型,模型计算值与实际测量值相吻合。随着锻造加热温度的升高,奥氏体晶粒长大呈现先缓慢增加后快速增加的规律。当锻造加热温度超过1150 ℃时,第二相粒子大量溶解,对晶界的钉扎作用急剧减弱。综合考虑20Cr2Ni4A钢锻后奥氏体晶粒尺寸均匀性、热处理后力学性能测试结果及可锻性因素,确定最优锻造加热温度为1150 ℃。

Effect of forging heating temperature on austenite grain growth and mechanical properties of 20Cr2Ni4A steel

Effects of forging heating temperature(1050-1200 ℃) and holding time(40-120 min) on grain growth behavior of austenite of the 20 Cr2 Ni4 A steel with same forging deformation were studied, and the mechanical properties of the quenched 20 Cr2 Ni4 A steel at different forging temperatures were tested. The results show that the austenite grain growth law of the 20 Cr2 Ni4 A steel after forging still conforms to the Beck model when the forging temperature is lower than 1150 ℃, and the model calculated value is consistent with the actual measured value. As the forging heating temperature increases, the growth of austenite grains shows a law of increasing slowly and then rapidly. When the forging heating temperature exceeds 1150 ℃, a large number of second phase particles dissolve and the pinning effect on grain boundaries decreases sharply. Considering the austenite grain size uniformity after forging, mechanical properties test results after heat treatment and forgeability factors of the 20 Cr2 Ni4 A steel, the optimal forging heating temperature is 1150 ℃.