Steel for molds and molding tool

A molding tool comprising following configurations:

• (1) the molding tool
• contains a mold or a mold component alone or a combination thereof and includes a portion that comes into direct contact with a workpiece having a temperature higher than room temperature;
• and
• (2) at least one of the mold or the mold component is formed of a mold steel comprising:
• 0.35<C<0.55 mass %,
• 0.003≤Si<0.300 mass %,
• 0.30<Mn<1.50 mass %,
• 3.10≤Cr<3.50 mass %,
• 0.003≤Cu<1.200 mass %,
• 0.003≤Ni<1.380 mass %,
• 1.46≤Mo≤2.99 mass %,
• 0.55<V<1.13 mass %, and
• 0.0002≤N<0.1200 mass %,
• with a balance being Fe and unavoidable impurities, and
• satisfying 0.55<Cu+Ni+Mo≤3.16 mass %, and has:
• a hardness being higher than 33 HRC and 57 HRC or lower,
• a grain size number of prior austenite being 5 or more after being heated to 1,030° C., held 5 hours, and then cooled,
• a thermal conductivity λ at 25° C. measured by using a laser flash method being higher than 27.0 [W/m/K], and
• the hardness of lower than 280 HV after being heated to 820° C. to 900° C., control-cooled to 600° C. at 15° C./hr, allowed to stand to cool to 100° C. or lower, and then heated to 630° C.