High strength steel sheet having excellent high-temperature elongation characteristic, warm-pressed member, and manufacturing methods for the same

A high strength steel sheet having excellent high-temperature elongation characteristics, comprising, by weight %:

• carbon (C):
• 0.4 to 0.9%,
• chromium (Cr):
• 0.01 to 1.5%,
• phosphorus (P):
• 0.03% or less (excluding 0%),
• sulfur (S):
• 0.01% or less (excluding 0%),
• nitrogen (N):
• 0.01% or less (excluding 0%),
• alkali-soluble aluminum (sol·Al):
• 0.10% or less (excluding 0%),
• a balance of iron (Fe) and inevitable impurities, and
• comprising at least one among manganese (Mn):
• 2.1% or less (excluding 0%), and silicon (Si):
• 1.6% or less (excluding 0%),
• wherein a microstructure comprises 80% or more of pearlite and 20% or less of ferrite by area fraction,
• wherein the pearlite comprises cementite having a major axis length of 200 nm or shorter, and
• wherein the cementite of the pearlite has an N value of 60% or more according to the following Relational Expression 2,
• N (%)=Nx/(Nx+Ny)*100 Relational Expression 2
• in the above Relational Expression 2, Nx is the number of cementite whose major axis length is 200 nm or less, and Ny is the number of cementite whose major axis length exceeds 200 nm.