Tempering process rules

Conditioning is heating quenching and high temperature tempering operation. Its purpose is to get a tempered sorbite, so as to improve the comprehensive mechanical properties of parts, also for nitrogen, the high frequency processing for organization to deal with in advance. Conditioning procedure is as follows: 1. The heating temperature of quenching and tempering temperature are shown in table a list of two points should be paid attention to when choosing temperature: 1) According to the surface conditions, forging stock selected limit scale thick, thin is limited in the first, rough turning light grey floor after 2) According to the cooling conditions, quenching water of lower limit, quenching oil had chosen cap of 2. Quenching heat preservation time choice: quenching the length of the heat preservation time on the basis of thermal conductivity of steel, the thickness and shape of the workpiece itself, furnace charging amount and way, the heating temperature decision, in accordance with the formula of t = a * k * D a¬ type; ¬ _____ the heating coefficient of k_____ furnace charging coefficient D_____ effective thickness of 3. The choice of coolant 1) Shape simple carbon steel in salt water or water cooling, 2) Complex shape of carbon steel and the effective thickness of coarser alloy steel. Adopt double liquid quenching ( Water - - - Oil or water - - Empty) Water - - - Oil quenching in water of the time the effective thickness of the 3 - to work 5 mm 1 seconds, water - - - Air quenching time is: < 30 mm diameter every 2 mm diameter> 1 SEC 30 mm per 1 mm more than 1 second refers to the workpiece reaches 200 ℃ in air cooling 3) Alloy steel phi < 30 ~ 50 mm is in the oil cooling, alloy tool steel in oil cooling, complex shape parts quenching oil temperature is not less than 30 ℃