600MPa级煤巷支护锚杆钢的开发与质量控制

Development and Quality Control of 600 MPa Steel Bar for Bolt Applied to Seam Gateway Support

针对我国锚杆用钢长期处于低强度、安全性能较差的现状,研发了屈服强度为600 MPa级的低屈强比、高强韧塑性煤巷支护锚杆钢。阐述了该钢种化学成分、微观物质结构、生产工艺路线设计思路;研究了热轧工艺下的低屈强比和高冲击韧性的影响因素,提出通过缩小动态再结晶区间降低混晶、控冷细化晶粒、洁净钢路线提高纯净度的生产控制工艺,实现了良好塑韧性。同时还提出通过控制多相钢组织为F(铁素体,53%)+P(珠光体)+M(马氏体)/A(奥氏体)、第二相纳米颗粒(10～30 nm)析出强化抗拉强度、F直径10～15μm,达到了屈强比不大于0.72的设计要求。并对钢中夹杂物实际控制水平、性能指标进行了评价。

According to the present status of the bolt bar steel long term with a low strength and poor safety performances,a low yield strength ratio and high tough plasticity bolt bar steel with a yield strength of 600 MPa was researched and developed for the seam gateway support.The paper stated the design ideas of the chemical compositions,micro material structure and the production technique route.The paper had a deep research on the influence factors to the low yield strength ratio and high impact toughness under the hot-rolling technique.The production control technique of the pureness could be improved with the reduction of the dynamic recrystallization zone to reduce the mixed crystal,the cooling controlled fined crystal particle and the clean steel rout and could have an excellent plastic toughness.Also with the controlled multi phase steel formation F（ferrite,53%） ＋P（pearlite） ＋M（martensite）/A（austenite） and the second phase nanoparticles（10~30 nm）,the intensified tensile strength was calculated,the F size was about 10~15 μm and the yield strength ratio reached the designed requirement not over 0.72.An evaluation on the actual controlled level of the inclusions in the steel and the performance index was conducted.