The present disclosure relates to a cast steel for construction equipment bucket parts and parts for a construction equipment bucket manufactured by using the same, and the cast steel includes 0.27 to 0.34 wt % of carbon (C), 1.2 to 1.8 wt % of chromium (Cr), 0.8 to 1.7 wt % of silicon (Si), 1.0 to 1.4 wt % of manganese (Mn), 0.2 to 0.4 wt % of molybdenum (Mo), 0.2 to 0.4 wt % of nickel (Ni), and a balance of iron and impurities.

To provide a ferritic stainless steel sheet which has high scale spalling even at a high temperature around 1000 C. Provided is a ferritic stainless steel sheet having excellent Mn-containing oxide film-forming ability and scale spalling ability, containing, in terms of mass %: C: 0.001 to 0.020%, N: 0.001 to 0.020%, Si: 0.10 to 0.40%, Mn: 0.20 to 1.00%, Cr: 16.0 to 20.0%, Nb: 0.30 to 0.80%, Mo: 1.80 to 2.40%, W: 0.05 to 1.40%, Cu: 1.00 to 2.50%, and B: 0.0003 to 0.0030%, in which the above-mentioned components are contained satisfying the formula (1) below, and the balance is composed of Fe and inevitable impurities. At least one of N, Al, V, Mg, Sn, Co, Zr, Hf, and Ta may be added in a predetermined content range.

3(5Mo)/(3Mn)20(1)

To provide a ferritic stainless steel sheet which has high scale spalling even at a high temperature around 1000 C. Provided is a ferritic stainless steel sheet having excellent Mn-containing oxide film-forming ability and scale spalling ability, containing, in terms of mass %: C: 0.001 to 0.020%, N: 0.001 to 0.020%, Si: 0.10 to 0.40%, Mn: 0.20 to 1.00%, Cr: 16.0 to 20.0%, Nb: 0.30 to 0.80%, Mo: 1.80 to 2.40%, W: 0.05 to 1.40%, Cu: 1.00 to 2.50%, and B: 0.0003 to 0.0030%, in which the above-mentioned components are contained satisfying the formula (1) below, and the balance is composed of Fe and inevitable impurities. At least one of N, Al, V, Mg, Sn, Co, Zr, Hf, and Ta may be added in a predetermined content range.

3(5Mo)/(3Mn)20(1)

Age hardening steel excellent in machinability before aging treatment and excellent in fatigue characteristics, toughness, and low cycle fatigue characteristics after aging treatment, that is, age hardening steel containing predetermined amounts of C, Si, Mn, S, Cr, Al, V, Nb, Ca, and REM, limiting contents of P, Ti, and N to predetermined amounts or less, having a balance of Fe and impurities, having an area ratio of bainite structures of 70% or more, and, furthermore, having a chemical composition where F1 expressed by C+0.3Mn+0.25Cr is 0.68 or more, F2 expressed by C+0.1Si+0.2Mn+0.15Cr+0.35V is 0.85 or less, F3 expressed by 4.5C+Mn+Cr3.5V is 0.00 or more, and F4 expressed by 10Ca+REM is 0.012 to 0.08, is provided. Note that, the symbols of elements in the formulas showing F1 to F4 mean the contents by mass % of those elements.

To provide a ferritic stainless steel sheet which has high scale spalling even at a high temperature around 1000 C. Provided is a ferritic stainless steel sheet having excellent Mn-containing oxide film-forming ability and scale spalling ability, containing, in terms of mass %: C: 0.001 to 0.020%, N: 0.001 to 0.020%, Si: 0.10 to 0.40%, Mn: 0.20 to 1.00%, Cr: 16.0 to 20.0%, Nb: 0.30 to 0.80%, Mo: 1.80 to 2.40%, W: 0.05 to 1.40%, Cu: 1.00 to 2.50%, and B: 0.0003 to 0.0030%, in which the above-mentioned components are contained satisfying the formula (1) below, and the balance is composed of Fe and inevitable impurities. At least one of N, Al, V, Mg, Sn, Co, Zr, Hf, and Ta may be added in a predetermined content range.
3(5Mo)/(3Mn)20(1)

To provide a ferritic stainless steel sheet which has high scale spalling even at a high temperature around 1000 C. Provided is a ferritic stainless steel sheet having excellent Mn-containing oxide film-forming ability and scale spalling ability, containing, in terms of mass %: C: 0.001 to 0.020%, N: 0.001 to 0.020%, Si: 0.10 to 0.40%, Mn: 0.20 to 1.00%, Cr: 16.0 to 20.0%, Nb: 0.30 to 0.80%, Mo: 1.80 to 2.40%, W: 0.05 to 1.40%, Cu: 1.00 to 2.50%, and B: 0.0003 to 0.0030%, in which the above-mentioned components are contained satisfying the formula (1) below, and the balance is composed of Fe and inevitable impurities. At least one of N, Al, V, Mg, Sn, Co, Zr, Hf, and Ta may be added in a predetermined content range.
3(5Mo)/(3Mn)20(1)

It is an objective of the present invention to provide a precipitation-hardening martensitic stainless steel having well-balanced properties of high mechanical strength, high toughness and good corrosion resistance properties. There is provided a precipitation-hardening martensitic stainless steel comprising: 0.10 mass % or less of C; 13.0 to 15.0 mass % of Cr; 7.0 to 10.0 mass % of Ni; 2.0 to 3.0 mass % of Mo; 0.5 to 2.5 mass % of Ti; 0.5 to 2.5 mass % of Al; 0.5 mass % or less of Si; 0.1 to 1.0 mass % of Mn; and the balance including Fe and incidental impurities, in which the mass % content of the Ti (represented by [Ti content]), the mass % content of the Al (represented by [Al content]) and the mass % content of the C (represented by [C content]) satisfy relationships of 0.5[Ti content]2.5 and 0.5[Al content]+2[C content]2.7.

It is an objective of the present invention to provide a precipitation-hardening martensitic stainless steel having well-balanced properties of high mechanical strength, high toughness and good corrosion resistance properties. There is provided a precipitation-hardening martensitic stainless steel comprising: 0.10 mass % or less of C; 13.0 to 15.0 mass % of Cr; 7.0 to 10.0 mass % of Ni; 2.0 to 3.0 mass % of Mo; 0.5 to 2.5 mass % of Ti; 0.5 to 2.5 mass % of Al; 0.5 mass % or less of Si; 0.1 to 1.0 mass % of Mn; and the balance including Fe and incidental impurities, in which the mass % content of the Ti (represented by [Ti content]), the mass % content of the Al (represented by [Al content]) and the mass % content of the C (represented by [C content]) satisfy relationships of 0.5[Ti content]2.5 and 0.5[Al content]+2[C content]2.7.

An alloy, including at least (in wt. %): carbon (C) 0.03%-0.08%, silicon (Si) 0.2%-0.4%, manganese (Mn) 1.6%-2.0%, molybdenum (Mo) 4.0%-5.0%, chromium (Cr) 20.0%-25.0%, nickel (Ni) 24.0%-27.0%, vanadium (V) 0.25%-0.35%, titanium (Ti) 2.0%-2.3%, aluminum (Al) 0.4%-0.6%, boron (B) 0.004%-0.006%, iron (Fe).

Material and method for the production of material with isotropic, mechanical properties and improved wear resistance and high hardness potential. Method includes producing in a powder metallurgical (PM) method a slug or ingot from a material of ledeburite tool steel alloy, and subjecting one of the slug or ingot or a semi-finished product produced from the slug or ingot to full annealing at a temperature of over 1100 C., but at least 10 C. below the fusing temperature of the lowest melting structure phase with a duration of over 12 hrs. In this manner, an average carbide phase size of the material is increased by at least 65%, a surface shape of the material is rounded and a matrix is homogenized. Method further includes subsequently processing the material into thermally tempered tools with high wear resistance occurs or into parts to which abrasive stress is applied.