Link plate balling and annealing technology

Abstract

The invention discloses a link plate balling and annealing technology which comprises the following steps of: putting a link plate on a tray in an inner barrel of a balling and annealing furnace and closing a furnace cover; heating the inner barrel to the temperature of 720 DEG C at the speed of 5 DEG C per minute; preserving the heat for 5 hours; slowly cooling the inner barrel to the temperature of 650 DEG C, and closing an air inlet valve to stop charging methanol gas; forcibly cooling the inner barrel to the temperature of 500 DEG C in 3 hours; and opening the furnace cover, hoisting the link plate out of the furnace, and cooling the link plate to normal temperature with air. The technology can ensure that the treated workpiece has good cutting performance, low hardness and high deformability, so that the quality and the service performance of the product are improved.

Description

technical field [0001] The invention relates to a chain plate spheroidizing annealing process. Background technique [0002] Metal heat treatment is to heat the metal workpiece to a suitable temperature in a certain medium, and keep it in this temperature for a certain period of time and then cool it in different medium at different speeds, and control its surface or internal microstructure by changing the metal material. A process of performance; spheroidizing annealing is an annealing method only applied to steel. The steel is heated to 20-30 °C above Ac1, kept for a period of time, and then slowly cooled to a temperature slightly lower than Ar1 and stayed for a period of time , the purpose is to make the flaky cementite and pro-eutectoid cementite in the pearlite become spherical and evenly distributed in the ferrite matrix. The medium carbon steel and high carbon steel with this structure have low hardness and are Good machinability and high cold deformation capacity; t...

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Problems solved by technology

[0002] Metal heat treatment is to heat a metal workpiece in a certain medium to a suitable temperature, and keep it at this temperature for a certain period of time, then cool it in a different medium at different speeds, and control its surface or internal microstructure by changing the metal material. A process of performance; among them, spheroidizing annealing is an annealing method only applied to steel, heating the steel to 20-30°C above Ac1, keeping it warm for a period of time, then slowly cooling to a temperature slightly lower than Ar1 and staying for a period of time , the purpose is to make the lamellar cementite and proeutectoid cementite in the pearlite become spherical and evenly distributed in the ferrite matrix. The medium carbon steel and high carbon steel with this structure have low hardness and are Good machinability and large cold deformation ability; the chain plate parts made of traditional 45 and 40Mn steel are stamped from hot-rolled steel plate after cold rolling; due to the organization of raw materials, banded and reticular pearlite structures often appear, and The hardness is very high, and it is necessary to add a raw material annealing process before stamping; the traditional annealing is complete annealing, and generally adopts 920 ℃ heat preservation for a certain period of time. In the annealing process, the holding temperature is high, the time is long, the waste of energy is great, and quality problems such as uneven hardness are prone to occur.

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