| 摘要 |
<p>Provided are: a high-strength hot-dip galvanized steel sheet having excellent workability and a tensile strength of at least 440 MPa; and a production method therefor. The structure of the steel sheet has a ferrite phase having an area ratio of at least 60%, a pearlite phase having an area ratio of 20%-30%, and a bainite phase having an area ratio of 1%-5%. The area ratio of a cementite phase inside the ferrite phase particles is no more than 5%. During production, a hot-rolled sheet or a cold-rolled sheet is heated to a temperature of at least 650°C at an average heating speed of at least 10°C/s, held at a temperature of 700-(AC3 - 5)°C for at least 10 s, cooled to a temperature range of 300-500°C at an average cooling speed of 10-200°C/s, and, after being held at the temperature range of 300-500°C for 30-300 s, is hot-dip galvanized.</p> |
