Powder for thermal spray, thermal spray coating film, coating film and roll in molten metal bath

A thermal spray powder comprising, as constituent elements:

• a first element selected from the group consisting of tungsten and molybdenum;
• a second element consisting of cobalt;
• a third element selected from the group consisting of carbon and boron;
• and
• a fourth element selected from the group consisting of aluminum and magnesium, wherein
• the thermal spray powder contains the second element in an amount of 20% by mole or greater,
• the mole ratio of the fourth element to the second element in the thermal spray powder is 0.05 or greater and 0.5 or less,
• the thermal spray powder has a crystal phase that contains cobalt;
• tungsten;
• and carbon or a crystal phase that contains cobalt;
• tungsten or molybdenum;
• and boron, and
• in an X-ray diffraction spectrum of the thermal spray powder, the intensity of a peak attributed to cobalt is at most 0.1 times the intensity of a peak having the largest intensity among peaks appearing in the same X-ray diffraction spectrum.