正火和淬火温度对30CrMoA钢除砂器大型锻件-40℃冲击韧性的影响

Effect of Normalizing and Quenching Temperature on -40℃Impact Toughness of Heavy Forging of Steel 30CrMoA for Desander

30CrMoA钢(/%:0.30C、0.21Si、0.53Mn、0.003S、0.005P、0.98Cr、0.22Mo、0.06V)除砂器锻件为外径Φ405～493 mm内径Φ90～167 mm的管状工件,技术条件要求调质后-40℃横向冲击功≥20 J。经常用正火+调质工艺920℃正火(风冷)+880℃正火(风冷)+860℃淬火(空冷+水冷)+630～680℃回火(空冷)后横向R_m715～815 MPa,R_(p0.2) 545～665 MPa,A 19%～20%,Z 65%～68%,室温A_(KC) 36～101 J,-40℃A_(KC) 11～21 J;通过Thermo-calc软件计算得出该钢平衡相图及计算的Ac_3温度确定优化调质工艺950℃正火(风冷)+820℃淬火(空冷+水冷)+660～670℃回火(空冷),其横向力学性能为R_m685～700 MPa,R_(p0.2)500～525 MPa,A 21%～22%,Z63%～66%,室温A_(KV) 65～114 J,-40℃A_(KC) 23～28 J,均符合技术条件要求。

The forging of steel 30CrMoA （/%： 0.30C, 0. 21Si, 0.53Mn, 0. 003S, 0. 005P, 0. 98Cr, 0. 22Mo, 0. 06V） for Desander is a tubular stock with outside diameter φ405 -493 mm and inside diameter φ90 - 167 mm and in specification the transverse impact energy of quenched-tempered steel at -40℃ is≥20 J. With conventional normalizing ＋ quenching-tempering process： 920℃ normalizing （fan cooling） ＋ 880 ℃ normalizing （fan cooling） ＋ 860℃ quenching （air cooling ＋ water cooling） ＋ 630～680℃ tempering （ air cooling） the transverse Rm of steel is 715～815 MPa, Rpo.2 545～665 MPa, A 19%～20%, Z 65%～68%, ambient AKV 36～101 J and～40℃ AKv 11～21 J; with equilibrium phase diagram calculated by Thermo-calc software and calculated Ac3 value of steel, the optimum normalizing ＋ quenchingtempering process has been defined that is 950℃ normalizing （ fan cooling） ＋ 820℃ quenching （ air cooling ＋ water cooling） ＋660-670℃ tempering （air cooling）, and with the optimum process the transverse mechanical properties of steel are Rm 685～700 MPa, Rp0.2 500 ～ 525 MPa, A 21%～22% , Z 63%～66% , ambient AKV 65～114 J and～40℃ AKV 23 28 J, all meet the requirement of specification for the steel.