| Title |
The Effects of Cooling Rate after Controlled Rolling on the Mechanical Properties of HSLA Line Pipe Steels |
| Authors |
김태웅(Tai Ung Kim); 김재은(Jae Eun Kim); 김영길(Young Gil Kim) |
| Abstract |
The effects of cooling rates after controlled rolling (C.R.) on the mechanical properties were investigated for the Mo-Ni-Nb-V type HSLA line pipe steels. The accelerated cooling was carried out after C.R. in the temperature range from 800℃ to 600℃ followed by air cooling. Cooling methods employed were air cooling (1.3℃/sec), compressed air cooling (4.1℃/S), oil quenching (9.5℃/S) and water spray cooling (13.6℃/S). It was found from this work that controlled rolled 0.3%Mo-0.3%Ni type steel exhibited 40% yield strength increments by water spray cooling, while impact energy was not changed greatly. For the conventionally rolled boron containing steel, impact energy at -20℃ was increased from about 3 to 17㎏f.m under water spray cooled condition. |