CN101748328A - Ship structure steel plate capable of being welded with high liner energy and method for producing same - Google Patents

Abstract

The invention relates to a ship structure steel plate capable of being welded with high liner energy and a method for producing the same, belonging to the technical field of the low-alloy high-strength steel. The ship structure steel plate comprises the following chemical components by weight percent (Wt%): 0.02-0.15 percent of C, 0.05-0.50 percent of Si, 0.50-2.0 percent of Mn, 0.10-0.50 percent of Ni, 0.01-0.15 percent of Nb, 0.01-0.15 percent of V, 0.01-0.08 percent of Ti, 0.002-0.015 percent of N, 0.01-0.5 percent of Al, 0.001-0.005 percent of B, 0.015 percent of P or less, 0.010 of percent of S or less and the balance of Fe and inevitable impurities. The method for producing the ship structure steel plate comprises the following steps: making molten iron or molten iron and waste steel into steel in a rotating furnace, refining the steel, deoxidizing the steel with Ti-Fe and Al wire, adjusting the components, continuously casting the steel into a steel plate slab and hot rolling the steel plate slab into a steel plate having the thickness of 18-80 mm by heating the steel plate slab to 1100-1300 DEG C and soaking steel plate slab for 2-6h, and cooling the steel plate on line at the cooling speed of 1-30 DEG C per second. The invention has the advantages that the welding efficiency of the steel plate can be effectively improved, the labor intensity can be reduced, the resource and the cost can be saved, and the steel plate can be used for the ship and other large-scale structures and facilities.

Description

But a kind of ship structure steel plate and manufacture method thereof of large-line energy welding

Technical field

The invention belongs to the low-alloy high-strength steel technical field, but relate to the ship structure steel plate and the manufacture method thereof of a kind of large-line energy welding (heat input is greater than 100kJ/cm).

Background technology

Global economic integration brings the sea transport amount and the energy consumption in the whole world constantly to increase, in order to improve conveying efficiency and to reduce the sea-freight burnup, to maximizing and the lightweight development, the shipbuilding efficiency that how further to improve shipyard is key subjects from now on to boats and ships always.On the other hand, all constantly surging to safety and environmental consciousness in the world, in shipbuilding field field of iron and steel, except satisfying the demand of high growth, the requirement that improves security and reliability is also more and more higher.Therefore, require ship structure steel plate satisfy the fragility of heat affected zone low, have that good cracking resistance line performance, heat affected zone are softening, high, the anti-yield strength height of fatigue resistance, excellent corrosion resisting performance is arranged, have and more require the welding efficiency height outside the good processing properties, can adapt to the large-line energy welding.

When traditional Low Alloy Steel Plate carries out the large-line energy welding,, cause toughness sharply to descend because the effect of Thermal Cycle is grown up unusually at welded heat affecting zone crystal grain.In addition, for traditional TMCP (thermomechanical treatment) technology, along with the raising of armor plate strength and the increase of thickness, must improve carbon equivalent (Ceq), this is the another factor that welding property and welding heat influence area toughness worsen.

Must consider the structural transformation characteristics of welded heat affecting zone during the large-linear energy welding low-alloy high-strength steel, some researchs at present relate to large-linear energy welding low-alloy high-strength steel and manufacture method thereof, as large-linear energy welding low-alloy high-strength steel (application number 02115877), unmodified high-toughness low-temp steel for high-energy line welding and production method (application number 01128316) thereof but can all there be following problem in the superstrength Plate Steel of large-line energy welding and manufacture method (application number 200410017255) thereof or the like:

1. weld heat input is low, and some can only be at 50～100kJ/cm.

2. some must adopt hardening and tempering process production, complex process, cost height.

3. some contains rare earth element, is not easy control.

4. use noble metal many in the steel, the cost height.

Summary of the invention

But the object of the present invention is to provide a kind of ship structure steel plate and manufacture method thereof of large-line energy welding, realized that production cost is lower, technology is simple, is easy to control.Can satisfy high strength, high tenacity, good welds processing performance, satisfy the large-line energy requirement of welding.

The chemical ingredients Wt%:C 0.02-0.15 of steel plate of the present invention; Si 0.05-0.50; Mn 0.50-2.0; Ni0.10-0.50; Nb 0.01-0.15; V 0.01-0.15; Ti 0.01-0.08; N 0.002-0.015; Al 0.01-0.5; B 0.001-0.005; P＜0.015; S＜0.010; All the other are Fe and unavoidable impurities.

Manufacturing process of the present invention is hot metal pretreatment → converter steelmaking → ladle deoxidation alloying → refining treatment (LF stove, RH stove, be tailored into and grade) → slab casting → slab slow cooling → heating → one time de-scaling → controlled rolling → controlled chilling → aligning → flaw detection → warehouse-in; The following processing parameter of control in technology:

Manufacturing process of the present invention is used Ti iron and the deoxidation of Al line for adopting converter with molten iron or molten iron and steel scrap refining after making steel, and adjusts composition, carries out continuous casting, hot rolling then.

Hot rolling technology is that slab is heated to 1100～1300 ℃, and soaking was carried out hot rolling in 2～6 hours, was rolled into 18～80mm Plate Steel, rolls the back with the online cooling of 1～30 ℃/s speed of cooling.

Owing to adopted advanced microalloy control techniques and TMCP technology, it is simple therefore to possess technology, is easy to control, lower-cost characteristics.The ship structure steel plate of its manufacturing satisfies tensile strength 600Mpa, and applicable to the large-line energy welding of 100～200kJ/cm heat input, postwelding does not need thermal treatment, and the ballistic work of heat affected zone is compared reduction with mother metal less.So steel plate possesses the welding efficiency height, crack sensitivity is low, and the characteristics that over-all properties is high can significantly improve efficiency, and save energy and material reduce cost.Steel plate can be applied to large scale structure and facilities such as boats and ships, is particularly useful for large-line energy welding processs such as shielded welding, union melt welding, electro-gas (enclosed) welding.

Embodiment

Embodiment 1:

Chemical ingredients Wt%:C 0.05; Si 0.20; Mn 1.50; Ni 0.25; Nb 0.04; V 0.03; Ti 0.03; N 0.007; Al 0.10; B 0.004; P＜0.010; S＜0.005; All the other are Fe and unavoidable impurities.

Manufacturing process of the present invention is hot metal pretreatment → converter steelmaking → ladle deoxidation alloying → refining treatment (LF stove, RH stove, be tailored into and grade) → slab casting → slab slow cooling → heating → one time de-scaling → controlled rolling → controlled chilling → aligning → flaw detection → warehouse-in; The following processing parameter of control in technology:

Adopt converter with molten iron or molten iron and steel scrap refining after making steel, use Ti iron and the deoxidation of Al line, and adjust composition, carry out continuous casting, hot rolling then;

Hot rolling technology is that slab is heated to 1200 ℃, and soaking was carried out hot rolling in 4 hours, was rolled into the 40mm Plate Steel, rolls the back with the online cooling of 15 ℃/s speed of cooling.

Present embodiment manufactured steel plates tensile strength is 600Mpa, and applicable to the large-line energy welding of 100～200kJ/cm heat input, postwelding does not need thermal treatment, and the ballistic work of heat affected zone is compared reduction with mother metal less.

Embodiment 2

Chemical ingredients Wt%:C 0.06; Si 0.30; Mn 1.60; Ni 0.30; Nb 0.02; V 0.10; Ti0.05; N 0.01; Al 0.20; B 0.003; P＜0.007; S＜0.003; All the other are Fe and unavoidable impurities.

Its manufacturing process is used Ti iron and the deoxidation of Al line for adopting converter with molten iron or molten iron and steel scrap refining after making steel, and adjusts composition, carries out continuous casting, hot rolling then.

Hot rolling technology is that slab is heated to 1250 ℃, and soaking was carried out hot rolling in 5 hours, was rolled into the 30mm Plate Steel, rolls the back with the online cooling of 10 ℃/s speed of cooling.

Present embodiment manufactured steel plates tensile strength is 650Mpa, and applicable to the large-line energy welding of 100～200kJ/cm heat input, postwelding does not need thermal treatment, and the ballistic work of heat affected zone is compared reduction with mother metal less.

Claims (2)

1. but the ship structure steel plate of a large-line energy welding is characterized in that chemical ingredients Wt% is: C 0.02-0.15; Si 0.05-0.50; Mn 0.50-2.0; Ni 0.10-0.50; Nb 0.01-0.15; V 0.01-0.15; Ti0.01-0.08; N 0.002-0.015; Al0.01-0.5; B 0.001-0.005; P＜0.015; S＜0.010; All the other are Fe and unavoidable impurities.

2. but method of making the ship structure steel plate of the described large-line energy of claim 1 welding, it is characterized in that manufacturing process is: hot metal pretreatment → converter steelmaking → ladle deoxidation alloying → refining treatment → slab casting → slab slow cooling → heating → one time de-scaling → controlled rolling → controlled chilling → aligning → flaw detection → warehouse-in; The following processing parameter of control in technology:

Adopt converter with molten iron or molten iron and steel scrap refining after making steel, use Ti iron and the deoxidation of Al line, and adjust composition, carry out continuous casting, hot rolling then;

Hot rolling technology is that slab is heated to 1100～1300 ℃, and soaking was carried out hot rolling in 2～6 hours, was rolled into 18～80mm Plate Steel, rolls the back with the online cooling of 1～30 ℃/s speed of cooling.