PURPOSE: To rationally and inexpensively perform the titled treatment in an energy conserving manner in a min. process and low equipment cost, by a method wherein soft steel or alloyed steel is soldered at a high temp. in a furnace and, after cooling in the furnace, the soldered steel is immersed in a chemical forming treatment tank due to MnP to form an anti-rust film.
CONSTITUTION: In a soldering furnace 1 equipped with a work charging chamber 2, a preheating furnace 3, a heating furnace 4 and a furnace cooling chamber 5, works are conveyed into a stand-by chamber 203 from an inlet part 201 by a conveyor 6. In the next step, a shutter 205 is opened to send the works into the furnace 3 held under a non-oxidative atmosphere to preheat the same. Subsequently, the works comprising soft steel or alloyed steel are sent into the furnace 4 held under a non-oxidative atmosphere to be heated to 800W1,200°C and soldering is performed in the furnace. Succeedingly, the treated works are cooled to a hardening temp. W100°C in the chamber 5 having a cooling pipe 502 arranged thereto. At last, the shutter 502 is opened to immerse the works in the MnP treating bath 802 in a chemical forming coating treatment tank 8 to form an anti-rust film.
NAKANISHI YASUO
NAGAMINE TAKASHI
| JPS5625903A | 1981-03-12 | |||
| JPS5639392A | 1981-04-15 | |||
| JPS55104473A | 1980-08-09 |