截齿用新型高硅低碳空冷贝氏体钢的组织与性能

Microstructure and properties of low-carbon air-cooling bainite steels with high Si used for pickers

为了克服常用 35 Cr Mn Si截齿原材料价格高、热处理工艺复杂、耗能大、污染环境、寿命低等缺点 ,设计了适合采煤机截齿用的高硅新型低碳空冷贝氏体钢 ,其成分 (质量分数 ,10 0× w) C为 0 .19～ 0 .2 7,Mn为 2 .0～ 4.0 ,B为0 .0 0 15～ 0 .0 0 3,Si为 0 .7～ 1.6。较高的硅含量提高了 Mn-B系贝氏体钢的空冷淬透性和韧性 ,较低的含碳量极大地提高了截齿的韧性和抗断裂能力。此钢经 116 3K奥氏体化后空冷 ,即可获得具有良好的高硬度、高韧性配合的贝氏体或贝氏体 /马氏体复相组织 ,其各项力学性能指标均达到或超过了采煤机截齿技术标准中的要求。新型空冷低碳贝氏体钢截齿 ,采用空冷硬化 ,工艺简单 ,免除了盐浴等温淬火 ,节约了能源 ,降低成本约 10 % ,并减少了污染。现场试验结果表明 :新型空冷低碳贝氏体钢截齿万吨耗齿量为 12 4件 ,齿体无弯曲和折断 ,比原 35 Cr Mn Si截齿可降低齿耗 8.

A new high Si and low carbon aircooled bainite steel (HSLCACBS) for coalexcavator pickers was designed to overcome the shortcomings of 35CrMnSi pickers, such as high raw material price, complex heat treatment, huge energy expense, serious environmental pollution and short lifespan. The composition (mass fraction, 100× w ) of the new material is C 0.19~0.27, Mn 2.0~4.0, B 0.0015 ~0.003, Si 0.7~1.6. Higher Si content increases the hardening ability and the toughness after aircooling. Lower carbon content greatly increases the toughness and ability to resistant fracture of the pickers. Cooling in air after austernization at 1163K produces the bainite or bainite/martensite composite microstructure with both high hardness and high toughness. All the HSLCACBS picker properties reach or exceed the regulations. The aircooling pickers have several advances, such as simple processing, no saltbath quenching, energy savings, reduced cost (10%) and reduced pollution. The results obtained in the testing mine show that 124 HSLCACBS pickers are needed for every 10000 tons of coal, 8.8% less than for the original 35CrMnSi pickers, with no bending and breaking of the picker handles.