Soft magnetic powder, Fe-based nanocrystalline alloy powder, magnetic component and dust core

1. A soft magnetic powder represented by composition formula of Fe a Si b B c P d Cu e except for inevitable impurities, wherein 79≤a≤84.5 at %, 0≤b<6 at %, 4≤c≤10 at %, 4<d≤11 at %, 0.2≤e<0.4 at % and a+b+c+d+e=100 at %,

wherein:

the soft magnetic powder is configured to be used as a starting material of an Fe-based nanocrystalline alloy powder which can be formed by applying heat-treatment to the soft magnetic powder;

the soft magnetic powder has an amorphous phase as a main phase;

the soft magnetic powder, before the heat-treatment, contains a crystal phase of at least 0.2 volume % and not more than 10 volume %;

the crystal phase consists of αFe crystals;

the soft magnetic powder includes Al, Ti, S, O and N as the inevitable impurities, the content of Al is not more than 0.1 mass % and not less than 0.001 mass %, the content of Ti is not more than 0.1 mass % and not less than 0.001 mass %, the content of S is not more than 0.1 mass % and not less than 0.002 mass %, the content of 0 is not more than 1.0 mass % and not less than 0.08 mass %, and the content of N is not more than 0.01 mass % and not less than 0.0005 mass %;

e/d is at most 0.07; and

due to the crystal phase contained in the soft magnetic powder, the soft magnetic powder represented by the composition formula is not suitable for forming a continuous strip.

2. The soft magnetic powder as recited in claim 1 , wherein 2≤b<6 at %.

3. The soft magnetic powder as recited in claim 2 , wherein 0.3≤e<0.4 at %.

4. The soft magnetic powder as recited in claim 2 , wherein 5<d≤11 at %.

5. The soft magnetic powder as recited in claim 2 , wherein not more than 3 at % of Fe is replaced with at least one element selected from Cr, V, Mn, Co, Ni, Zn, Nb, Zr, Hf, Mo, Ta, W, Ag, Au, Pd, K, Ca, Mg, Sn, C, Y and rare-earth elements.

6. The soft magnetic powder as recited in claim 1 , wherein 0.3≤e<0.4 at %.

7. The soft magnetic powder as recited in claim 6 , wherein 0.35≤e<0.4 at %.

8. The soft magnetic powder as recited in claim 7 , wherein 5<d≤11 at %.

9. The soft magnetic powder as recited in claim 7 , wherein not more than 3 at % of Fe is replaced with at least one element selected from Cr, V, Mn, Co, Ni, Zn, Nb, Zr, Hf, Mo, Ta, W, Ag, Au, Pd, K, Ca, Mg, Sn, C, Y and rare-earth elements.

10. The soft magnetic powder as recited in claim 6 , wherein 5<d≤11 at %.

11. The soft magnetic powder as recited in claim 6 , wherein not more than 3 at % of Fe is replaced with at least one element selected from Cr, V, Mn, Co, Ni, Zn, Nb, Zr, Hf, Mo, Ta, W, Ag, Au, Pd, K, Ca, Mg, Sn, C, Y and rare-earth elements.

12. The soft magnetic powder as recited in claim 1 , wherein 5<d≤11 at %.

13. The soft magnetic powder as recited in claim 1 , wherein not more than 3 at % of Fe is replaced with at least one element selected from Cr, V, Mn, Co, Ni, Zn, Nb, Zr, Hf, Mo, Ta, W, Ag, Au, Pd, K, Ca, Mg, Sn, C, Y and rare-earth elements.

14. The soft magnetic powder as recited in claim 1 , wherein the content of Al is not more than 0.01 mass % and not less than 0.001 mass %, the content of Ti is not more than 0.01 mass % and not less than 0.001 mass %, the content of S is not more than 0.05 mass % and not less than 0.002 mass %, the content of O is not more than 0.3 mass % and not less than 0.08 mass %, and the content of N is not more than 0.002 mass % and not less than 0.0005 mass %.

15. The soft magnetic powder as recited in claim 1 , wherein the soft magnetic powder contains the crystal phase of at least 0.2 volume % and not more than 3 volume %.

16. An Fe-based nanocrystalline alloy powder made by using the soft magnetic powder as recited in claim 1 as a starting material.

17. A magnetic component comprising the Fe-based nanocrystalline alloy powder as recited in claim 16 .

18. A dust core comprising the Fe-based nanocrystalline alloy powder as recited in claim 16 .