Shanghai Daoqin Plastics Co., Ltd.

        1, add hot speed degree effect/influence

         generally 说, add hot 时, add hot speed degree fast, mold in generate hot force large, easy formed mold deformation cracking, especially for/regarding alloy and high alloy 钢, its thermally conductive property 差, attention/notes preheating, for/regarding 一 形状 complex high alloy mold, also 需采取 more separation grade preheating.

        但 in 别情况 lower, using/adopting fast speed add hot has 时反而 can decrease/reduce deformation, this add hot mold surface, in also maintain “ cold 态”, therefore versus decrease/reduce 组织应 force and hot force, 且心部 deformation resistant force relatively large, from decrease/reduce deformation, according to factory experience, used for solution deformation has 一定效果.

        2, add hot temperature degree effect/influence

        淬火 add hot temperature degree high low effect/influence material property, meanwhile for 奥氏体 formed separation and large small function.

        (1) from property 方面看, add hot temperature degree high, will make hot force increase large, meanwhile make property increase high, therefore 组织应 force increase large, 并逐渐占主导 位. 例如. carbon tool 钢T8, T10, T12 and other, in generally temperature degree 淬火时, inner performance is shrink toward, improve/increase temperature degree to ≥850℃时, due to property increase large, 组织应 force 逐渐占主导 位, inner can can performance is 胀 倾 toward.

        (2) from 奥氏体 formed separation 看, temperature degree improve/increase make 奥氏体含 carbon amount increase, rear 马氏体 positive degree increase large (ratio increase large), from make rear increase large.

        (3) from for Ms点 effect/influence fine 看, temperature degree high, 则奥氏体晶粒 coarse large, will make parts deformation cracking toward increase large.

         comprehensive upper 述, for has types, especially is certain high carbon in, high alloy 钢, temperature degree high low obvious effect/influence mold deformation, therefore, positive selection add hot temperature degree is very important.

         generally 说, selection high add hot temperature degree for deformation is has benefits. in effect/influence use property can front lower, is using/adopting relatively low add hot temperature degree. for 一 淬火 rear has relatively more 残余奥氏体 钢号(如Cr12MoV and other), can through adjustment add hot temperature degree, 改变残余奥氏体 amount, adjustment mold deformation.

        3, cooling speed degree effect/influence

        总 说, in Ms点 above increase large cold speed, make hot force significantly increase, make hot force deformation toward increase large; in Ms点 below/following increase large cold speed main/primary make 组织应 force deformation toward increase large.

         for/regarding different types, due to Ms点 high low different, in using/adopting 同一淬火介质时, has different deformation toward. 同一钢 types using/adopting different 淬火介质, due to it cooling can force different, 因而也 has different deformation toward.

        例如, carbon tool in Ms点 comparison low, using/adopting water cold 时, hot force effect/influence 往往占 upper 风;而 using/adopting cold 时, can can is 组织应 force upper 风.

         in production in, mold using/adopting separation grade or separation grade - and other temperature 淬火时, usually 均未完 full 淬透, 故往往以 hot force function is 主, make type 腔趋于 shrinkage, due to this hot force is very large, therefore deformation amount is comparison small. using/adopting water -油 di liquid or 油淬时, hot force relatively large, type shrinkage amount will increase large.

        4, temperature degree effect/influence

        回火 temperature degree for deformation effect/influence, main/primary is due to process in 组织转变 引起. in process in generate “二次淬火” phenomenon, 残余奥氏体转变 is 马氏体, due to formed 马氏体 ratio ratio 残余奥氏体 large, will mold type 腔 胀 large; for high alloy tool 钢如Cr12MoV and other, requirements hard property is using/adopting high temperature 淬火, more 次回火时, one-time 火, 体积就胀 large one-time.

        若 in other temperature degree 区域回火, due to 淬火马氏体 toward 回火马氏体(or 回火索氏体, 回火屈氏体 and other)转变, ratio decrease small, 因而, type toward shrinkage.

         another, 回火时, mold in residual stress 松弛, for deformation has effect/influence. mold rear, surface 处于拉应 force 状态, rear dimensions will increase large;反之, surface pressure force 状态, generate shrinkage. 但组织转变 and force 松弛两项 effect/influence in, front is main/primary.