Korea Sintered Metal Co., Ltd.

Hyundai Motor Company

Kia Motors Corporation

Jong Kwan Park

Ki Bum Kim

Jae Woo Lee

Shin Gyu Kim

Sung Kweon Jang

Ki Jung Kim

Eui Jun Kim

Sung Tae Choi

Young Su Jeon

Disclosed herein is an engine valve seat, including: iron (Fe) as a main component; about 0.6&#x2dc;1.2 wt % of carbon (C); about 1.0&#x2dc;3.0 wt % of nickel (Ni); about 8.0&#x2dc;11.0 wt % of cobalt (Co); about 3.0&#x2dc;6.0 wt % of chromium (Cr); about 4.0&#x2dc;7.0 wt % of molybdenum (Mo); about 0.5&#x2dc;2.5 wt % of tungsten (W); about 1.0&#x2dc;3.0 wt % of manganese (Mn); about 0.2&#x2dc;1.0 wt % of calcium (Ca); and other inevitable impurities.

Engine valve seat and manufacturing method thereof

A high frequency heat treatment method for a fine bottom-closed hole includes preparing a coil so as to be completely inserted into the fine bottom-closed hole, preparing a core for controlling a magnetic flux within the coil such that the core protrudes from upper and lower sides of the coil, heat-treating a target part of the fine bottom-closed hole under conditions of a heating time of 2&#x2dc;3 seconds, an output power of 200&#x2dc;300 kW, a quenching time of 3&#x2dc;5 seconds, a positive electrode voltage of 4 &#x2dc;8 kV, and a positive electrode current of 2.0&#x2dc;4.5 A, and quenching the heat-treated part of the fine bottom-closed hole with cooling nozzles fixed around the heat-treated part such that a sufficient amount of cooling water is injected uniformly over the whole heated part with a sufficient pressure via the cooling nozzles.

High frequency heat treatment method for fine bottom-closed hole

Growing community of inventors

Daegu, South Korea

Jong Kwan Park