| 摘要: |
| 采用Mg-Ti复合氧化物冶金处理方式试制了40mmQ500MC钢板,并进行了热输入为276KJ/cm的大线能量焊接实验。结果表明,钢板各项力学性能满足GB/T1591要求,且韧脆转变温度VTE低于-60℃。焊接接头各项力学性能满足标准要求,热影响区各位置0℃、-20℃冲击韧性满足标准要求且有一定余量。对比母材,焊接热影响区0℃冲击功降低约56%,-20℃冲击功降低约77%,热影响区韧脆转变温度VTE约为-18.4℃。经过大线能量焊接后,粗晶热影响区获得以晶内针状铁素体为主的组织,韧性水平较理想,热影响区正火区域宽度可达5-6mm,组织以铁素体+珠光体为主,对应区域硬度较低,软化严重。 |
| 关键词: Q500MC 大线能量焊接 气电立焊 冲击功 软化 |
| DOI： |
| 分类号:TG115.5 |
| 基金项目: |
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| Experimental Study on Large Heat-Input Welding Properties of 40mm Q500MC Steel Plate |
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Qu Zhiguo
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日钢营口中板有限公司
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| Abstract: |
| A study on large heat-input welding of 40mm Q500MC steel plate was conducted using Mg-Ti composite oxide metallurgical treatment to produce the 40mm Q500MC steel plate, and a large heat-input welding experiment was conducted with a heat input of 276KJ/cm. The results show that the mechanical properties of the steel plate meet the requirements of GB/T1591, and the ductile brittle transition temperature (vTE) is lower than -60 ℃. The mechanical properties of the welded joint meet the standard requirements too, and the impact toughness at 0 ℃ and -20 ℃ in each position of the heat affected zone meets the standard requirements with a certain margin. Compared to the base material, the impact energy of the welding heat affected zone at 0 ℃ is reduced by about 56%, and the impact energy at -20 ℃ is reduced by about 77%. The toughness to brittleness transition temperature (vTE) in the heat affected zone is about -18.4 ℃. After high heat-input welding, the coarse grain heat affected zone obtains a structure mainly composed of intragranular acicular ferrite, with an ideal toughness level. The width of the normalized zone in the heat affected zone can reach 5-6mm, and the structure is mainly composed of ferrite and pearlite. The corresponding area has low hardness and severe softening. |
| Key words: Q500MC Large heat-input welding EGW Impact energy Softening. |
