手工具用熱冷軋高碳合金鋼開發

The Development of Hand-tool Grade Hot-and Cold-Rolled High Carbon Alloy Steels

王元聰(Y. T. Wang) ； 林守杞(S. C. Lin) ； 李炳坤(P. K Lee) ； 黃慶淵(C. Y. Huang)

《鑛冶：中國鑛冶工程學會會刊》 55卷3期 (2011/09) Pp. 20-29

https://doi.org/10.30069/MM.201109.0002

摘要

為兼顧手工具產品之高硬度及高韌性需求，以發揮高耐磨、抗高溫軟化與使用壽命長的特性，手工具用高碳鋼與合金鋼有迫切開發的需求。然隨著碳含量超過共析點（0.8wt％C）與合金添加量提高，所形成硬脆網狀碳化物對鋼材延韌性與加工性會造成嚴重傷害。本研究利用雙束離子束電子顯微鏡（FIB-SEM），並結合三維電腦輔助軟體，以重建波來鐵組織之立體影像，以釐清促使碳化物形成完全球狀化機制之關鍵因素。為得到優良鋼材性能組合，本研究高碳鋼材採適量微合金複合添加之設計，並配合熱軋控制軋延，採低完軋高捲溫方式，以利生成細小網狀、初析與合金碳化物。另再藉由適當退火製程溫度與時間控制，使碳化物能充份固溶與析出，以得到完全球狀化利於加工之碳化物組織型態。經適當淬火回火熱處理，組織中大量均勻分佈之鉻、鉬碳化物，使鋼材耐磨耗、抗高溫軟化與韌性顯著提升。此手工具鋼材已被廣泛應用於園藝工具、鋸片、刀具及捲尺等高品級產品上。

關鍵字

高碳合金鋼 ； 網狀碳化物 ； 完全球狀化 ； 耐磨耗 ； 抗高溫軟化

並列摘要

High carbon alloy steels are in a good demand for making hand tools that have excellent wear resistance, anti-high temperature softening, and long life time. When the carbon content is over 0.8 wt% and the alloy additive is increased, the hard and brittle net-work of carbides reduces the toughness and suitability for manufacturing. We investigated the carbide spheroidization of the high carbon alloy steels using FIB-SEM and computer-aided three-dimensional (3D) tomography. We constructed the 3D images and clarified the elements contributing to the formation of pearlite spheroiization. To obtain the excellent quality of the high carbon alloy steels, we have (1) added appropriate amount of alloy composites, (2) subjected the slab to a special hot-rolling process with a low finishingrolling temperature and a high coiling temperature, (3) subjected the slab to proper annealing temperature for an appropriate time, and (4) subjected the slab to heat treatment of quench and temper process. A fully spheroidized microstructure that has good cold-forming property was obtained. The large amount of chromium and molybdenum carbide dispersed in temper martensite obviously improved the abrasion resistance, high temperature anti-softening properties and toughness. The hot- and cold-rolled high carbon alloy steels have been used to manufacture high quality garden tools, saws, knifes and tape measures.

並列關鍵字

High carbon alloy steel ； Net-work carbide ； Fully carbide spheroidization ； Abrasion resistance ； High temperature anti-softening property