Of the defect when heat treatment of mould rolled steel guard against

The heat treatment of the mould included preparation heat treatment, after all heat treatment and outside aggrandizement processing. Normally heat treatment defect is to show the mould is in after all heat treatment process medium or the working procedure henceforth is medium and all sorts of defect that in using a process, appear, if temper by dipping in water is cracked, the early days attaint that is out of shape lack of out of tolerance, rigidity, report machines crackle of craze, grinding, mould. Make below more detailed analyse.

Temper by dipping in water is cracked

The element that temper by dipping in water cracks and precautionary measures are as follows:

1, appearance effect, basically program element is formed, if round horn R crosses azimuth of small, cavity to install misgivings, sectional transfer had owed.

2, overheat (burn) too, basically be by accuse lukewarm forbid or run element of imparity of exorbitant, furnace temperature forms temperature of setting of lukewarm, technology, precautionary measures includes maintenance, proofread control lukewarm system, correct technical temperature, mat iron is added to wait between workpiece and furnace motherboard.

3, decarbonization, main by overheat (or burn too) , air furnace is not had safeguard heat, machine increase surplus small, cast or prepare the element such as decarburized layer of heat treatment remain to form, precautionary measures heats to can accuse atmosphere, saline bath heats, vacuum furnace, box type furnace chooses case to safeguard or apply antirust coating; Machine mental allowance increases 2 ～ 3mm.

4, cooling misgivings, basically be refrigerant chooses misgivings or super-cooling is formed, ought to hold quench cooling character or temper handle medium.

5, arrangement of mould rolled steel is undesirable, if carbide slants analyse is serious, cast quality difference, misgivings of method of preparative heat treatment, precautionary measures is to choose cast technology and system of sound preparative heat treatment well and truly.

2, rigidity lack. The element that hardness lacks and precautionary measures are as follows:

1, quench temperature passes low, because the technology installs temperature misgivings,basically be, accuse lukewarm system error, outfit furnace or enter the element such as misgivings of cooling chamfer method to form, ought to correct technical temperature, maintenance school nucleus controls lukewarm system, when installing furnace, workpiece is apart from manage of separation and reunion to put even, lax enters groove, check pile up or become bunch of refrigeration that enter groove.

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