A tool steel having strength and high impact toughness incudes 0.7 to 0.9 wt % of C, 0.4 to 0.6 wt % of Si, 0.4 to 0.6 wt % of Mn, 7.0 to 9.0 wt % of Cr, 1.5 to 2.5 wt % of Mo, up to 1.0 wt % or less (excluding 0 wt %) of V, 0.01 to 0.06 wt % of Ce, and a remainder of Fe and inevitable impurities, wherein the tool steel has a hardness of 59 to 65 HRC and an impact toughness of 30 to 42 J/cm.sup.2. The tool steel has super-high-strength combined with high impact toughness due to inclusion of Ce, thus reducing primary carbide content in an as-cast state and after solution treatment and tempering.

A tool steel having strength and high impact toughness incudes 0.7 to 0.9 wt % of C, 0.4 to 0.6 wt % of Si, 0.4 to 0.6 wt % of Mn, 7.0 to 9.0 wt % of Cr, 1.5 to 2.5 wt % of Mo, up to 1.0 wt % or less (excluding 0 wt %) of V, 0.01 to 0.06 wt % of Ce, and a remainder of Fe and inevitable impurities, wherein the tool steel has a hardness of 59 to 65 HRC and an impact toughness of 30 to 42 J/cm.sup.2. The tool steel has super-high-strength combined with high impact toughness due to inclusion of Ce, thus reducing primary carbide content in an as-cast state and after solution treatment and tempering.

The invention relates to a stainless steel blank for making a Damascus patterned article, wherein the steel blank is made from at least two different nitrogen alloyed stainless steels having a chromium content of 11-25 weight %, of which at least one of the steels comprises nitrogen in an amount of 0.10-5.0 weight % and, optionally, at least one of the steels comprises nitrogen in an amount of 0.01-0.5 weight %.

A sickle cutting section is provided. The sickle cutting section comprises a plate having a base material of a first hardness. The plate extends forwardly from a mounting portion to a front tip. A serrated cutting edge extends at least partially between the front tip and the mounting portion. A clad material is of a second hardness that is harder than the first hardness and is deposited along the base material at least partially along the serrated cutting edge.

A sickle cutting section is provided. The sickle cutting section comprises a plate having a base material of a first hardness. The plate extends forwardly from a mounting portion to a front tip. A serrated cutting edge extends at least partially between the front tip and the mounting portion. A clad material is of a second hardness that is harder than the first hardness and is deposited along the base material at least partially along the serrated cutting edge.

Disclosed is super-high-strength tool steel having high impact toughness, including 0.7 to 0.9 wt % of C, 0.4 to 0.6 wt % of Si, 0.4 to 0.6 wt % of Mn, 7.0 to 9.0 wt % of Cr, 1.5 to 2.5 wt % of Mo, 1.0 wt % or less (excluding 0 wt %) of V, and at least one of 0.1 wt % or less (excluding 0 wt %) of Ti and 0.1 wt % or less (excluding 0 wt %) of Ce, with the remainder of Fe and inevitable impurities. The super-high-strength tool steel having high impact toughness includes at least one of Ti and Ce, thus reducing primary carbide content in an as-cast state and exhibiting improved impact toughness at a high hardness level after solution treatment and tempering. In addition, a method of manufacturing super-high-strength tool steel having improved impact toughness at a high hardness level is provided.

Disclosed is super-high-strength tool steel having high impact toughness, including 0.7 to 0.9 wt % of C, 0.4 to 0.6 wt % of Si, 0.4 to 0.6 wt % of Mn, 7.0 to 9.0 wt % of Cr, 1.5 to 2.5 wt % of Mo, 1.0 wt % or less (excluding 0 wt %) of V, and at least one of 0.1 wt % or less (excluding 0 wt %) of Ti and 0.1 wt % or less (excluding 0 wt %) of Ce, with the remainder of Fe and inevitable impurities. The super-high-strength tool steel having high impact toughness includes at least one of Ti and Ce, thus reducing primary carbide content in an as-cast state and exhibiting improved impact toughness at a high hardness level after solution treatment and tempering. In addition, a method of manufacturing super-high-strength tool steel having improved impact toughness at a high hardness level is provided.

A method for manufacturing a steel strip for a blade and a steel strip for a plate, said method includes a batch annealing step for annealing a material for cold rolling having the aforementioned metal composition in a batch annealing furnace and a cold rolling step for forming a steel strip by performing cold rolling one or more times on the material for cold rolling that has been batch annealed. The batch annealing step includes a first uniform temperature step for maintaining heating for 1 to 12 hours at an internal furnace temperature exceeding 450 C. and less than 770 C. and a second uniform temperature step, carried out after the first uniform temperature step, for maintaining heating for 1 to 16 hours at an internal furnace temperature exceeding 770 C. and less than 900 C.

The present invention discloses a method of manufacturing a tool with a cutting edge comprising a substrate for supporting and a cladding layer for forming the cutting edge, and a transition zone connecting the substrate and the cladding layer; the method of manufacturing it includes: providing a first material used for forming the substrate and having a first side; providing a second material which is clad onto the first side by way of laser cladding to form the cladding layer, and forming a transition zone between the cladding layer and the substrate where the first material and the second material are metallurgically bonded. The tool obtained by adopting the manufacturing process according to the present invention combines the following advantages: good toughness of the cutter body, high hardness of the cutting edge, not easy breaking off of the cutter body and the cutting edge, and long service life.

The present invention discloses a method of manufacturing a tool with a cutting edge comprising a substrate for supporting and a cladding layer for forming the cutting edge, and a transition zone connecting the substrate and the cladding layer; the method of manufacturing it includes: providing a first material used for forming the substrate and having a first side; providing a second material which is clad onto the first side by way of laser cladding to form the cladding layer, and forming a transition zone between the cladding layer and the substrate where the first material and the second material are metallurgically bonded. The tool obtained by adopting the manufacturing process according to the present invention combines the following advantages: good toughness of the cutter body, high hardness of the cutting edge, not easy breaking off of the cutter body and the cutting edge, and long service life.