1、 Excessive polishing: the problem encountered in the daily polishing process is "excessive polishing", which means that the longer the polishing time, the worse the quality of the mold surface. There are two phenomena of excessive polishing: orange peel and pitting. Excessive polishing often occurs in mechanical polishing.

二、工件"橘皮"的措施：當發現表麵（miàn）質量拋得不（bú）好時，許多（duō）人就會（huì）增加拋（pāo）光的（de）壓力（lì）和延長拋光的時（shí）間，這種作法往往會使表（biǎo）麵的質量變得差。可（kě）采用以下的方法去補救：

2、 Measures to eliminate the "orange peel" of workpieces: when it is found that the surface quality is not polished well, many people will increase the polishing pressure and prolong the polishing time, which often makes the surface quality worse. The following methods can be used to remedy:

(1)把有缺陷的（de）表麵去除，研磨的粒度比先前使用砂號略粗一級，然（rán）後進行（háng）研磨，拋光的力度要（yào）比先前（qián）的低一些。

(1) Remove the defective surface, grind the particle size slightly thicker than the previous sand number, and then grind it. The polishing force is lower than the previous one.

(2)以低（dī）於回火（huǒ）溫度25℃的溫度進行應力（lì），在拋光前使用細的砂號進行研（yán）磨，以較輕的力度進行拋光。

(2) Stress relief shall be carried out at a temperature 25 ℃ lower than the tempering temperature. Before polishing, grind with a fine sand number and polish with a light force.

三、工件表麵"點蝕"形成的原因

3、 Causes of "pitting corrosion" on workpiece surface

由於在鋼材中有些非金屬（shǔ）的雜質，通常是硬而脆的氧（yǎng）化物，在（zài）拋光過程中從鋼材表麵被拉出，形成微（wēi）坑或點蝕，產（chǎn）生"點蝕（shí）"的主要因（yīn）素有以下幾點：

Some non-metallic impurities in steel, usually hard and brittle oxides, are pulled out from the steel surface during polishing to form micro pits or pitting corrosion. The main factors causing "pitting corrosion" are as follows:

(1)拋光（guāng）的壓力過大，拋光時間過長。

(1) The polishing pressure is too high and the polishing time is too long.

(2)鋼材的純淨度不夠，硬（yìng）性雜質的含量（liàng）高。

(2) The purity of steel is not enough and the content of hard impurities is high.

(3)模（mó）具表麵生鏽。

(3) The mold surface is rusty.

(4)黑皮料未。

(4) The black leather is not removed.

（5）小心地將表麵重（chóng）新研磨，砂粒粒度比（bǐ）先（xiān）前所（suǒ）使用的（de）粒度略粗一（yī）級，采用軟質及削銳的油石進行後步驟的研磨才再進行拋光程序（xù）。

(5) Carefully regrind the surface. The sand particle size is slightly thicker than that previously used. Use soft and sharp oilstone for subsequent grinding before polishing.

（6）當砂粒尺寸小於（yú）1mm應避免采用軟的拋光工具。

(6) When the sand size is less than 1mm, soft polishing tools shall be avoided.

（7）盡可能采用短的拋光時間和小的拋光力（lì）度。

(7) Use as short polishing time and small polishing force as possible.

工件出現"橘皮"的原因：不規則粗糙的表麵被稱為"橘皮"，產生"橘皮"有（yǒu）許多（duō）的原因，常見的原因是由於模（mó）具表麵過熱或滲碳過度而引起，拋光壓力過大及拋光時（shí）間過長是（shì）產生"橘（jú）皮"的主要（yào）原因。比如：拋光輪拋光，拋光輪產生的熱量會很容易造成"橘皮"。較硬的鋼材能承受的（de）拋光壓力會大一些，相對較軟的鋼材容易發生拋（pāo）光過度，研究證明產（chǎn）生拋光過度的時間會因鋼材的硬度不同而有所不同。

Reasons for "orange peel" of workpiece: irregular and rough surface is called "orange peel". There are many reasons for "orange peel". The common reasons are caused by overheating or excessive carburization of mold surface. Excessive polishing pressure and too long polishing time are the main reasons for "orange peel". For example: polishing wheel polishing, the heat generated by the polishing wheel will easily cause "orange peel". The harder steel can bear more polishing pressure, and the softer steel is prone to over polishing. The research shows that the time of over polishing varies with the hardness of the steel.