针对中厚板连铸坯出现的热送裂纹问题,提出了正常生产条件下的防治措施.对于已有中厚板主要品种,通过成分,计算不同钢种相变温度,并根据现场实际生产情况进行修正,最终确定了中厚板连铸坯的热送工艺制度.经现场生产实践,微合金化钢连铸坯实现了热装热送,热送比率能够稳定在76％以上,达到了节约能耗、降低成本的目的.
In order to meet market demand and diversify the product structure, based on the requirement on properties of high strength, high plasticity, good cold forging ability and easy drawing, study was carried on for the chemical composition, heating system and controlled rolling and cooling process of wire rod. Hot rolled wire rod produced by SWRCH35K cold heading steel was successfully developed. Production practice indicated its mechanical properties, metallographic structure, surface quality and cold forging property all met the requirements by the standard and the production requirements of the customer.
为了满足市场需求,在S355系列钢板的标准要求基础上,根据不同质量级别的要求设计化学成分,严格控制炼钢和连铸工艺,实现了碳元素的窄成分控制,通过控制轧制工艺及轧后钢板的热处理,成功研制开发出欧标S355系列钢板,具有优良的内部组织.熔炼分析和金相检验表明,钢板夹杂物含量较少,晶粒均匀细小,综合性能优异,能够符合标准要求.
The influential factors and process control methods of steel plate impact toughness are introduced in the paper.Plate impact properties are used to measure the ability of steel plate to bear impact load and resist breakage and influenced by many factors such as chemical composition,metallographic structure,non-metallic inclusions and processes of steel-making,rolling and heat treatment and so on.In order to increase the impact toughness of steel plate,structure uniformity and steel cleanliness must be improved by converter strengthened smelting,white slag refining,submerge casting and TMCP rolling process.
在少量添加和不添加钒的两种成分条件下,采用低温轧制和快速冷却的工艺试制了HRB400E抗震盘螺.对试制产品进行了力学性能和高倍组织的检验.试制结果表明:加钒盘螺屈服强度在430～455 MPa范围内,未加钒盘螺屈服强度在410 ～ 430 MPa范围内,综合力学性能良好,盘螺金相组织主要为铁素体和珠光体,完全能够满足抗震钢筋的要求.
In order to adapt itself to the development situation of high speed railway construction in China,Tianjin Iron and Steel Group Company Limited successfully trailed and developed high speed wire rod specialized for sleeper slab wire application through market investigation,technical plan elaboration and critical process control.The paper explains the whole process in detail.Inspection shows all property indices meet quality requirement.The sleeper slab wire manufactured by the mentioned wire rod gives good and stable properties,meets the demand of the train at 350 km/h speed and presents vast market prospect.
