Low-alloy hot rolling rolled plate for bending machining and preparing method of low-alloy hot rolling rolled plate

Abstract

The invention belongs to the technical field of steel materials, and particularly relates to a low-alloy hot rolling rolled plate for bending machining and a preparing method of the low-alloy hot rolling rolled plate. Chemical components of the rolled plate comprise, by weight percent, 0.08%-0.12% of C, 0.40%-0.60% of Mn, 0.040%-0.060% of Ti, smaller than or equal to 0.30% of Si, smaller than or equal to 0.010% of S, smaller than or equal to 0.025% of P, smaller than or equal to 0.0070% of N, and the balance Fe and inevitable impurities, and the rolled plate is prepared through the technologyprocess of molten iron pretreatment, top and bottom combined blowing converter smelting, LF refining, continuous casting, heating furnace heating, rough rolling, fine rolling, laminar cooling and curling. The disclosed low-alloy hot rolling rolled plate for bending machining has the beneficial effects of excellent crack arrest performance, good uniform plasticity and the like, the usage requirement of a user for cracking avoiding during bending machining can be met, and meanwhile compared with the production cost of Q345B steel in the prior art, the production cost of the low-alloy hot rollingrolled plate is relatively maintained to be consistent.

Description

technical field [0001] The invention belongs to the technical field of iron and steel materials, and in particular relates to a low-alloy hot-rolled coil plate for bending processing and a preparation method thereof. Background technique [0002] Low-alloy steel is the most basic and widely used steel type, and it is also one of the steel types with the largest output of plates and coils in national enterprises and private enterprises. With the rapid development of the national economy and the great improvement of infrastructure, the use of structural engineering steel involves all aspects, and the processing methods are not limited to structural welding. To reduce production costs, various cold forming processes such as bending, stamping, and suspension pressure are also used for low-alloy steel. The bending and stamping processing of low alloy steel has a high cracking rate, and there are situations where the steel meets the standard and is not suitable for use. At prese...

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Problems solved by technology

With the rapid development of the national economy and the great improvement of infrastructure, the use of structural engineering steel involves all aspects, and the processing methods are not limited to structural welding. To reduce production costs, various cold forming processes such as bending, stamping, and suspension pressure are also used for low-alloy steel. The bending and stamping processing of low alloy steel has a high cracking rate, and the steel material meets the standard and is not suitable for use.

At present, the low-alloy Q345 grade hot-rolled coil is generally a medium-carbon high-manganese plus micro-alloyed composition system, and the continuous rolling process is used in the processing process, which results in significantly poor lateral properties of the material, resulting in bending cracks during subsequent bending processing high rate

[0003] According to the applicant's market and product performance research, the requirements for low-alloy hot-rolled coil steel for bending processing are as follows: in terms of material performance, it must meet the performance requirements of GB / T 1591 Q345 grade steel; in terms of user requirements, it is necessary to ensure that the material is in good condition. Excellent toughness, uniform plasticity and low anisotropy to reduce the cracking rate of bending processing; in terms of production cost, the user's acceptance must be considered, and it must be equivalent to the cost of the original low-alloy Q345B coil or not increase much, otherwise the user will not Accepted; other requirements: the specification thickness is generally less than 12mm, and the surface quality is good, but the low-alloy Q345B coils in the prior art obviously do not meet the needs of users

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