高温服役3×105h后汽缸螺栓用20Cr1Mo1V1钢的应力松弛性能
Stress Relaxation of 20Cr1Mo1V1 Steel for Cylinder Bolt after Working for 3×105 h at High Temperature
-
摘要: 利用等强度环法测定了在540 ℃、9.8 MPa下服役3×105 h后汽缸螺栓用20Cr1Mo1V1钢在不同初紧应力下, 540 ℃保温不同时间后的应力松弛曲线, 外推得到了该钢保温1×104, 3×104, 1×105 h松弛后的应力值, 并与标准规定的不漏蒸汽时的最小应力值进行了对比。结果表明: 采用319.51 MPa的初紧力对已服役3×105 h的汽缸螺栓进行紧固可基本保证在一个大修期间内汽缸不漏蒸汽。Abstract: Stress relaxation curves of 20Cr1Mo1V1 steels for cylinder bolt after working for 3×105 h at 540 ℃ and 9.8 MPa were measured by equal-strength loop method under different initial tighten strains. The stress relaxation values of this steel at 540 ℃ for 1×104, 3×104 , 1×105 h were given through extrapolation method. The results show that cylinder bolts made by 20Cr1Mo1V1 steel after working for 3×105 h were tight enough under the initial pressure of 319.51 MPa to guarantee no-leak in an overhaul period basically.
下载: