The present invention relates to an air conditioner. The air conditioner according to the present embodiment has a refrigeration capacity of 16 kW to 28 kW, inclusive, and uses a single refrigerant R32 as a refrigerant, and a refrigerant pipe therein includes a ductile stainless steel pipe having 1% or less of a delta-ferrite matrix structure with respect to the grain size area thereof.

The present invention relates to an air conditioner. The air conditioner according to the present embodiment has a refrigeration capacity of 7 kW to 11 kW, inclusive, and uses a refrigerant R134a as a refrigerant, and since a refrigerant pipe therein is made of a ductile stainless steel material having 1% or less of a delta-ferrite matrix structure with respect to the grain size area thereof, and includes a suction pipe guiding the suction of the refrigerant into a compressor and having an outer diameter of 15.88 mm, the refrigerant pipe can maintain strength and hardness as good as or better than those of a copper pipe, while also maintaining good processability.

The present invention relates to an air conditioner. The air conditioner according to the present embodiment has a refrigeration capacity of 2 kW to 7 kW, inclusive, and uses R410a as a refrigerant circulating therein, and since a refrigerant pipe therein includes a ductile stainless steel pipe made of a material containing, at least, chrome (Cr), nickel (Ni), manganese (Mn) and copper (Cu), the refrigerant pipe can maintain strength and hardness as good as or better than those of a copper pipe, while also maintaining good processability.

The present invention relates to an air conditioner. The air conditioner according to the present embodiment has a refrigeration capacity of 11 kW to 16 kW, inclusive, and uses R32 as a refrigerant circulating therein, and since a refrigerant pipe therein is made of a ductile stainless steel material having 1% or less of a delta-ferrite matrix structure with respect to the grain size area thereof, the refrigerant pipe can maintain strength and hardness as good as or better than those of a copper pipe, while also maintaining good processability.

An air conditioner according to the present embodiment includes: an outdoor unit including a compressor, an outdoor heat exchanger, and a main expansion device, wherein a refrigerant is circulated by a refrigerant pipe configured to connect the compressor, the outdoor heat exchanger, and the main expansion device, an indoor unit including an indoor heat exchanger; and a connection pipe configured to connect the outdoor unit and the indoor unit, wherein the air conditioner has a cooling capability between 23 kW and 35 kW, a mixed refrigerant containing R32 of 50% or more is used as the refrigerant, and the refrigerant pipe comprises a ductile stainless steel pipe having a delta ferrite matrix structure of 1% or less on a basis of a grain area.

Disclosed is a method for manufacturing a corrosion-resistant hot-stamping part and a device thereof. The method includes the following steps: blanking a bare steel plate into a required blank shape; heating the blank to above AC3 in an oxygen-free heating furnace to austenite the blank; putting the austenitized blank into a mold to mold a part; and conducting a surface treatment of the part to form a corrosion-resistant coating layer on a surface of the part. The hot-stamping part manufactured using the described method has good surface quality and great corrosion-resistant performance

The linear groove formation method includes a resist forming process of forming a coated resist on a surface of a steel sheet, a laser irradiating process of irradiating laser beams onto the steel sheet while repeating a laser scanning in a direction intersecting a rolling direction of the steel sheet cyclically in the rolling direction of the steel sheet to remove the coated resist in portions irradiated with the laser beams, and an etching process of forming linear grooves by etching portions of the steel sheet from which the coated resist is removed. In the laser irradiating process, the coated resist is removed by using two or more laser irradiating devices, with a certain irradiation energy, a certain beam diameter in a direction perpendicular to a laser scanning direction, and a certain incidence angle with respect to the surface of the steel sheet.

A guiding member, having a body provided with a bore for mounting a mobile element is presented. The body consists of a metallic material. The bore has a surface layer treated against jamming over a diffusion depth of less than or equal to 0.6 mm. The surface layer has a hardness of greater than or equal to 500 Hv1 over a depth of between 5 and 50 μm.

The present invention relates to an air conditioner. The air conditioner according to the present embodiment has a refrigeration capacity of 11 kW to 16 kW, inclusive, and uses R134a as a refrigerant circulating therein, and since a refrigerant pipe therein is made of a ductile stainless steel material having 1% or less of a delta-ferrite matrix structure with respect to the grain size area thereof, the refrigerant pipe can maintain strength and hardness as good as or better than those of a copper pipe, while also maintaining good processability.

An amorphous alloy particle is an amorphous alloy particle formed of an iron-based alloy, and the particle contains a grain boundary layer.