| 摘要 |
FIELD: process engineering. ^ SUBSTANCE: invention relates to production of rolled stock, particularly, to thermal treatment of coiled strip from high-strength low-carbon steel. Coiled strips are heated with standing at preset temperature and duration, followed by cooling and metal unsqueezing. Note here that to produce steel containing carbon of 0.03 to 0.05 wt % and with â""=340 to 400 MPa, heating is carried out to 680C, as per stand thermocouple, and with standing at said temperature to lagging point temperature of 660C, volume of blowdown hydrogen making at least 2.8 "é" of metal. Note also that to produce steel containing 0.06 to 0.08 wt % of carbon with c â""=380 to 440 MPa, heating is conducted till 680C with interval of standing at said temperature equal to half the total time of metal standing and consequent cooling to 660, as per stand thermocouple, and standing to lagging point temperature of 630C. Note that water cooling in initiated, in both cases, at 280C, while metal unsqueezing is conducted at lagging point temperature of 140C. ^ EFFECT: higher quality of coiled strip. ^ 2 ex |
