Hot rolled steel sheet for roller of rotary compressor and the method thereof and the roller made of the hot rolled steel sheet and the method thereof

摘要

PURPOSE: To provide a rotor for rotary compressor having wear resistance by heat treating the pipe formed strip after forming a hot rolled strip with a certain controlled alloy element composition into a cylindrical pipe shape, a manufacturing method of the rotor, hot rolled strip excellent in weldability required for manufacturing rotor according to the manufacturing method, and a manufacturing method of the hot rolled strip, thereby preventing growth of crack during welding and offering weldability capable of enduring high-speed rotational friction. CONSTITUTION: The hot rolled strip for rotor of rotary compressor comprises 0.30 to 0.45 wt.% of C, 0.10 to 0.50 wt.% of Si, 0.60 to 1.50 wt.% of Mn, 0.0010 to 0.0050 wt.% of B, 0.10 to 0.50 wt.% of Cr, and the balance being Fe and inevitable impurities. The manufacturing method of the rotor for rotary compressor comprises a step of making a slab by casting molten steel comprising 0.30 to 0.45 wt.% of C, 0.10 to 0.50 wt.% of Si, 0.60 to 1.50 wt.% of Mn, 0.0010 to 0.0050 wt.% of B, 0.10 to 0.50 wt.% of Cr, and the balance being Fe and inevitable impurities; a step of heating the slab to a temperature of 1100 to 1250 deg.C; a step of hot rolling the heated slab in the temperature range of 840 to 900 deg.C; a step of cooling the hot rolled strip to a temperature of 600 to 680 deg.C; a step of forming the cooled strip into a pipe through welding; a step of oil quenching the heated formed strip to a temperature of 60 to 90 deg.C after heating the formed strip to a temperature of 860 to 900 deg.C for 30 to 90 minutes; a step of tempering the quenched strip at a temperature of 200 to 350 deg.C for 60 to 90 minutes; and a step of cooling the tempered strip in air.