1077 Каталог KORLOY 2016 Металлорежущий инструмент и станочная оснастка ENG Стр.L10

Каталог KORLOY 2016 Инструмент и оснастка Стр. L10 1077 ENG Lab2u

General Information I Technical information for Stainless steel Guide of stainless-steel machining Stainless steels well known for their excellent anti-corrosive property. Excellent anti-corrosive property is due to the Chromium added to these alloys. In general, stainless have 4% 10% Chromium content. Classifications & Features of Stainless steel. 1) Austenite series One of the most general kinds of stainless steels, it has some of the best corrosion-resistance properties due to a high Chromium & Nickel content. A high Nickel content also makes machining more difficult. Austenite series stainless steels are usually used for can processing, chemical products and construction purposes. (AISI 303,304,316) 2) Ferrite series It has Chromium content similar to Austenite series, but none of the Nickel content which results in freer machining. (AISI 410,430,434) 3) Martensite series The only stainless steel with the ability to be heat treated. It has a high carbon content but poor corrosion resistance, so it is used for parts that need higher hardness. (AISI410, 420,432) 4) Precipitate hardened series AChromium-Nickel alloy, it has improved hardnessthrough lowtemperature heat-treatment and has superior corrosion resistance and toughness at the same time. (AIS117,15) 5) Austenite-Ferrite series Though it has similar properties with Austenite and Ferrite, it has much more superior heat-resistance (approx. 2 times better). Usually used where thermal-corrosion stability is needed, such as condensers (AISI S2304, 2507). Difficult-to-Cut Factors of Stainless steel. 1) Work-hardening property - Causes premature wear of tool and poor control chip. 2) Low thermal conductivity - Causes plastic deformation of cutting edge and fast wear of tools. 3) Built-up-edge - More susceptible to micro-chipping on cutting edges and causes bad surface-finish. 4) Chemical affinity between tool and workpiece caused by work-hardening and low thermal-conductivity of workpiece, this might generate abnormal-wear, chipping and/or abnormal fracture. Tips for Machining of Stainless steel. 1) Use a tool that has higher thermal-conductivity Low thermal-conductivity of stainless steels accelerates tool wear resulting from a decline in hardness of the cutting edge of an insert, this is due to heat piling up. It is better to use a tool that has higher thermal conductivity and with enough coolant. 2) Sharper cutting edge-line It is necessary to utilize larger rake-angles and wider chip-breaker lands to reduce cutting-load pressure and prevent build-up-edge. This will help provide better chip control. 3) Optimal cutting condition Inappropriate machining conditions like extremely low or high-speeds or low feed rates can cause poor tool life due to work-hardening of work piece. 4) Choose an appropriate tool Tools for stainless steels should have good toughness attributes, enough strength on their edge-line (cutting edge) & a higher film adhesion.