Welding method of high manganese steel and 9ni dissimilar steel

Abstract

The application discloses a welding method for high manganese steel and 9Ni dissimilar steel, adopts arc welding, welding current is 110-130 A, arc voltage is 21-24 V, welding speed is 10-13 cm / min, welding heat input is 10-18 kJ / cm; interlayer temperature is not more than 100 DEG C. The welding groove is X type, the groove angle is 60-70 DEG, the groove blunt edge thickness is 0-2 mm, and the groove gap is 0-2 mm. The welding seam and the heat affected zone of the method have the impact energy KV2 of not less than 27 J at -196 DEG C, the tensile strength of not less than 680 MPa, the longitudinal face bending d of the welding joint of equal to 4a, and the 180 DEG is qualified, so that the mechanical properties required in various low-temperature environments are met; the process window is appropriate, the operability is high, special equipment and process conditions are not needed, and the method is suitable for processing of various specifications of steel plates.

Description

TECHNICAL FIELD

[0001] The present application relates to a welding method of high manganese steel and 9Ni dissimilar steel, in particular to a welding method of high manganese steel and 9Ni dissimilar steel suitable for thick steel plate and excellent in mechanical properties of welded joint. BACKGROUND

[0002] High manganese steel is required to be used partially on auxiliary structure (such as connecting piece) of 9Ni steel tank body, so high manganese steel and 9Ni dissimilar steel need to be welded and connected to form structure for low temperature storage and transportation tank and the like. Meanwhile, mature dissimilar steel welding method of high manganese steel as tank body has not been formed, and automatic welding cannot be realized in manufacturing process due to design features of structure. Whether the above dissimilar steel welding has a wide welding process window, joint performance after welding, especially low temperature impact toughness of welded joint, needs to consider the influence of base material dilution, and meanwhile, hardening structure in weld needs to be avoided. SUMMARY

[0003] The present application aims to provide a welding method of high manganese steel and 9Ni dissimilar steel suitable for low temperature medium storage and transportation.

[0004] Technical scheme: the welding method of high manganese steel and 9Ni dissimilar steel of the present application comprises the following steps:

[0005] (1) preparing steel plate and welding material;

[0006] (2) welding: adopting arc welding, welding current is 110-130A, arc voltage is 21-24V, welding speed is 10-13cm / min, and welding heat input is 10-18kJ / cm; interlayer temperature is not more than 100℃;

[0007] (3) cleaning root treatment, welding the other side;

[0008] Wherein, the welding groove is X type, the groove angle is 60-70°, the groove bevel thickness is 0-2mm, and the groove gap is 0-2mm.

[0009] Preferably, the thickness of the above steel plate is 16-30mm, more preferably 16mm, 20mm and 30mm.

[0010] Preferably, the above-mentioned groove angle is 60-65°, more preferably 60°, 65°, and most preferably 65°; the ratio of the groove face thickness to the groove gap is 1:2-2:1, more preferably 1:2, 2:1; wherein the groove face thickness is most preferably 1-2mm, and the groove gap is most preferably 0.5-2mm; specifically, the groove face thickness is 1mm and the groove gap is 0.5mm, or the groove face thickness is 1mm and the groove gap is 2mm.

[0011] Preferably, the above-mentioned welding heat input is 10kJ / cm, 14kJ / cm, 18kJ / cm; and the interpass temperature is 40-100℃, more preferably 45-100℃.

[0012] Preferably, the welding current is 110A, 120A, 130A; the arc voltage is 21V, 24V, more preferably 24V; and the welding speed is 10cm / min, 12cm / min, 13cm / min.

[0013] No preheating is required before welding, and the back welding needs to be performed after the root face is cleaned.

[0014] Preferably, the diameter of the welding material is 3.2mm.

[0015] Preferably, the composition of the high manganese steel contains, in terms of mass percentage, C: 0.35%-0.55%, Mn: 22%-26%, Si: 0.10%-0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0%-4.0%, Cu: 0.3%-0.7%, and the balance of Fe and inevitable impurity elements; the yield strength is ≥400MPa, the tensile strength is ≥800-970MPa, the elongation is ≥22%, the impact energy KV2 at -196℃ is ≥27J, and more than 95% of the microstructure is austenite.

[0016] The composition of the welding material contains C: ≤0.10%, Mn: 2.0%-4.0%, Si: ≤1.0%, S: ≤0.015%, P: ≤0.02%, Ni: 55.0-60.0%, Cr: 12.0-17.0%, Mo: 5.0-9.0%, V: ≤0.01%, and the balance of Fe and inevitable impurity elements; the deposited metal has an impact energy KV2 at -196℃ of ≥55J, and the tensile strength of the welding wire is ≥620MPa.

[0017] 9Ni steel contains C: ≤0.10%, Mn: 0.30%~0.80%, Si: 0.15%~0.35%, S: ≤0.004%, P: ≤0.008%, Ni: 8.5%~10.0%, Mo: ≤0.10%, the rest is Fe and inevitable impurity elements; yield strength ≥585MPa, tensile strength ≥680~820MPa, elongation ≥18%, -196℃ impact energy KV2 ≥100J.

[0018] Beneficial effects: compared with the prior art, the present application has the following remarkable advantages:

[0019] 1. The austenite grains in the weld and heat-affected zone are not obviously increased, which can ensure the mechanical properties, -196℃ impact energy KV2 ≥27J, tensile strength ≥680MPa, and the longitudinal face bending d of the welded joint is 4a, 180° qualified, which meets the mechanical properties required in various low-temperature environments.

[0020] 2. The welding is carried out by using electrode arc welding, the electrode accessibility is good, the process window is appropriate, the operability is strong, special equipment and process conditions are not required, and the processing of various specifications of steel plates is suitable. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a structural schematic view of a welding groove.

[0022] Figure 2 It is a microstructure structure diagram of a welded joint. DETAILED DESCRIPTION

[0023] The technical solutions of the present application are further described below in combination with examples.

[0024] Example 1

[0025] A welding process using Ni-based welding material suitable for welding high manganese steel and 9Ni dissimilar steel includes the following steps:

[0026] The base material uses high-manganese steel with the following composition: C: 0.35%–0.55%, Mn: 22%–26%, Si: 0.10%–0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0%–4.0%, Cu: 0.3%–0.7%, with the balance being Fe and unavoidable impurity elements. Its yield strength is ≥400MPa, tensile strength is ≥800–970MPa, elongation is ≥22%, and impact energy at -196℃ (KV2) is ≥27J. The base material also includes high-manganese steel with the following composition: C: ≤0.10%, Mn: 0. 30%~0.80%, Si: 0.15%~0.35%, S: ≤0.004%, P: ≤0.008%, Ni: 8.5%~10.0%, Mo: ≤0.10%, with the balance being Fe and unavoidable impurity elements; yield strength ≥585MPa, tensile strength ≥680~820MPa, elongation ≥18%, and impact energy at -196℃ KV2≥100J. 9Ni is butt-welded, with a test plate assembly of 16mm+16mm and test plate dimensions of 500mm (length) × 200mm (width) × 16mm (thickness).

[0027] The welding material selected is Ni-based welding electrode with a diameter of Φ3.2mm. The low-temperature impact energy (KV2) of the deposited metal at -196℃ is ≥55J, and the tensile strength of the welding wire is ≥620MPa. The chemical composition and weight percentage of the welding electrode are as follows: C: ≤0.10%, Mn: 2.0~4.0%, Si: ≤1.0%, S: ≤0.015%, P: ≤0.02%, Ni: 55.0~60.0%, Cr: 12.0~17.0%, Mo: 5.0~9.0%, V: ≤0.01%, with the balance being Fe and unavoidable impurities.

[0028] The bevel type is X-type bevel, the bevel angle is 60°, the blunt edge is 1mm, and the bevel assembly gap is 2mm;

[0029] No preheating is required before welding; interpass temperature is 40–100℃. Before welding on the reverse side, the root is cleaned with a grinding wheel to give the root a metallic luster.

[0030] The welding method used was shielded metal arc welding (SMAW), with a welding current of 110A, an arc voltage of 21V, a welding speed of 13cm / min, and a welding heat input of 10kJ / cm.

[0031] Example 2

[0032] A welding process using Ni-based welding materials suitable for welding high-manganese steel and 9Ni dissimilar steel includes the following steps:

[0033] The base material is high manganese steel with a composition comprising C: 0.35% to 0.55%, Mn: 22% to 26%, Si: 0.10% to 0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0% to 4.0%, Cu: 0.3% to 0.7%, and the balance of Fe and inevitable impurity elements, and 9Ni with a composition comprising C: ≤0.10%, Mn: 0.30% to 0.80%, Si: 0.15% to 0.35%, S: ≤0.004%, P: ≤0.008%, Ni: 8.5% to 10.0%, Mo: ≤0.10%, and the balance of Fe and inevitable impurity elements, and the yield strength is ≥400 MPa, the tensile strength is ≥800 to 970 MPa, the elongation is ≥22%, and the impact energy KV2 at -196°C is ≥27 J, which are butt-welded, and the welding test plate combination is 20 mm+20 mm, and the test plate size is 500 mm (length) x 200 mm (width) x 20 mm (thickness);

[0034] The welding material is a Ni-based welding rod with a diameter of Φ3.2 mm, and the deposited metal has an impact energy KV2 at -196°C of ≥55 J, and the tensile strength of the welding wire is ≥620 MPa, and the chemical composition of the welding rod is as follows: C: ≤0.10%, Mn: 2.0 to 4.0%, Si: ≤1.0%, S: ≤0.015%, P: ≤0.02%, Ni: 55.0 to 60.0%, Cr: 12.0 to 17.0%, Mo: 5.0 to 9.0%, V: ≤0.01%, and the balance of Fe and inevitable impurities;

[0035] The diameter of the welding rod is Φ3.2 mm;

[0036] The groove type is X-type groove, the groove angle is 65°, the bevel is 1 mm, and the groove assembly gap is 0.5 mm;

[0037] No preheating before welding, and the interlayer temperature is 45 to 100°C; the back welding is treated by a grinder to remove the root, and the root is metallic luster;

[0038] The welding is carried out by arc welding, the welding current is 120 A, the arc voltage is 24 V, the welding speed is 12 cm / min, and the welding heat input is 14 kJ / cm.

[0039] Example 3

[0040] A welding process for welding high manganese steel and 9Ni dissimilar steel using a Ni-based welding material comprises the following steps:

[0041] The base material is high manganese steel with a composition comprising C: 0.35% to 0.55%, Mn: 22% to 26%, Si: 0.10% to 0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0% to 4.0%, Cu: 0.3% to 0.7%, and the balance of Fe and inevitable impurity elements, and 9Ni with a composition comprising C: ≤0.10%, Mn: 0.30% to 0.80%, Si: 0.15% to 0.35%, S: ≤0.004%, P: ≤0.008%, Ni: 8.5% to 10.0%, Mo: ≤0.10%, and the balance of Fe and inevitable impurity elements, and the yield strength is ≥400 MPa, the tensile strength is ≥800 to 970 MPa, the elongation is ≥22%, and the impact energy KV2 at -196°C is ≥27 J, and the butt joint is welded, and the welding test plate combination is 30 mm+30 mm, and the test plate size is 500 mm (length) x 200 mm (width) x 30 mm (thickness);

[0042] The welding material is a Ni-based welding rod with a diameter of Φ3.2 mm, and the deposited metal has an impact energy KV2 at -196°C of ≥55 J, and the tensile strength of the welding wire is ≥620 MPa, and the chemical composition of the welding rod is as follows: C: ≤0.10%, Mn: 2.0 to 4.0%, Si: ≤1.0%, S: ≤0.015%, P: ≤0.02%, Ni: 55.0 to 60.0%, Cr: 12.0 to 17.0%, Mo: 5.0 to 9.0%, V: ≤0.01%, and the balance of Fe and inevitable impurities;

[0043] The diameter of the welding rod is Φ3.2 mm;

[0044] The groove type is an X-type groove, the groove angle is 65°, the bevel is 1 mm, and the groove assembly gap is 0.5 mm;

[0045] No preheating before welding, and the interlayer temperature is 45 to 100°C; the back welding is treated by a grinder to remove the root, and the root is metallic luster;

[0046] The welding is carried out by arc welding, the welding current is 130 A, the arc voltage is 24 V, the welding speed is 10 cm / min, and the welding heat input is 18 kJ / cm.

[0047] Comparative Example 1

[0048] A welding process for welding high manganese steel and 9Ni dissimilar steel using a Ni-based welding material comprises the following steps:

[0049] The base material is high manganese steel with a composition comprising C: 0.35% to 0.55%, Mn: 22% to 26%, Si: 0.10% to 0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0% to 4.0%, Cu: 0.3% to 0.7%, and the balance of Fe and inevitable impurity elements, and 9Ni with a composition comprising C: ≤0.10%, Mn: 0.30% to 0.80%, Si: 0.15% to 0.35%, S: ≤0.004%, P: ≤0.008%, Ni: 8.5% to 10.0%, Mo: ≤0.10%, and the balance of Fe and inevitable impurity elements, and the yield strength is ≥400 MPa, the tensile strength is ≥800 to 970 MPa, the elongation is ≥22%, and the impact energy KV2 at -196°C is ≥27 J, and the welding test plate combination is 30 mm + 30 mm, and the test plate size is 500 mm (length) x 200 mm (width) x 30 mm (thickness);

[0050] The welding material is a Ni-based welding rod with a diameter of Φ 3.2 mm, and the deposited metal has an impact energy KV2 at -196°C of ≥55 J, and the tensile strength of the welding wire is ≥620 MPa, and the chemical composition of the welding rod is as follows: C: ≤0.10%, Mn: 2.0 to 4.0%, Si: ≤1.0%, S: ≤0.015%, P: ≤0.02%, Ni: 55.0 to 60.0%, Cr: 12.0 to 17.0%, Mo: 5.0 to 9.0%, V: ≤0.01%, and the balance of Fe and inevitable impurities;

[0051] The diameter of the welding rod is Φ 3.2 mm;

[0052] The groove type is X-type groove, the groove angle is 65°, the bevel is 1 mm, and the groove assembly gap is 0.5 mm;

[0053] No preheating before welding, and the interlayer temperature is 45 to 100°C; the back welding is treated by a grinder before welding, and the root is metallic luster;

[0054] The welding rod arc welding is adopted, the welding current is 130 A, the arc voltage is 24 V, the welding speed is 9 cm / min, and the welding heat input is 20 kJ / cm.

[0055] Example 4

[0056] The high manganese steel and 9Ni dissimilar steel were welded by the welding method of the above-mentioned examples 1-3 and comparative example 1, and the mechanical properties of the welded joints were detected according to GB / T 2651-2008, GB / T 2653-2008 and GB / T 2650-2008. The impact, tensile and bending properties of the welded joints are shown in Table 1.

[0057] Table 1. Impact properties of the welded joints

[0058]

[0059]

[0060] Table 2. Tensile and side bending properties of the welded joints

[0061]

[0062] From Table 1-Table 2 and Figure 2 It can be seen that the comprehensive mechanical properties of the welded joints of the welding method of examples 1-3 are excellent, the austenite grains of the weld and the heat-affected zone are not obviously increased, and the mechanical properties can be ensured. The impact energy KV2 of the weld and the heat-affected zone at-196℃ is ≥27J, the tensile strength (Rm) is ≥680MPa, the longitudinal face bending d of the welded joint is =4a, and 180° is qualified. However, the impact energy KV2 of the weld of the welding method of comparative example 1 at-196℃ is <27J, which does not meet the requirements. With the increase of heat input, the high-temperature residence time is long, and the heat-affected zone is overheated to a large extent, which leads to the decrease of impact toughness, which shows that the welding parameters of the high manganese steel and the 9Ni dissimilar steel should not be too large. The present application adopts Ni welding rod welding, the welding current is 110-130A, the arc voltage is 21-24V, the welding speed is 10-13cm / min, and the welding heat input is controlled in 10-18kJ / cm, which are all the preferred parameter conditions.

Claims

1. A welding method of high manganese steel and 9Ni dissimilar steel, characterized by, The method comprises the following steps: (1) preparing a base material and a welding material: the base material is a steel plate, and the welding material contains, in mass percentage, C: ≤0.10%, Mn: 2.0%-4.0%, Si: ≤1.0%, S: ≤0.015%, P: ≤0.02%, Ni: 55.0-60.0%, Cr: 12.0-17.0%, Mo: 5.0-9.0%, V: ≤0.01%, and the balance of Fe and inevitable impurity elements; the deposited metal has a low-temperature impact energy KV2 at 196 ℃ of ≥55 J, and the tensile strength of the welding wire is ≥620 MPa; (2) welding: adopting arc welding, the welding current is 110-130 A, the arc voltage is 21-24 V, the welding speed is 10-13 cm / min, and the welding heat input is 10-18 kJ / cm; the interlayer temperature is not higher than 100 ℃; (3) root cleaning treatment, and welding the other side; wherein the welding groove is X-shaped, the groove angle is 60-70°, the groove land thickness is 0-2 mm, and the groove gap is 0-2 mm.

2. The welding method according to claim 1, characterized in that, The steel plate has a thickness of 16-30 mm.

3. The welding method of claim 1, wherein, The groove angle is 60-65°, and the ratio of the groove land thickness to the groove gap is 1:2-2:

1.

4. The welding method according to claim 3, characterized in that, The groove land thickness is 1-2 mm, and the groove gap is 0.5-2 mm.

5. The welding method of claim 3, wherein, The groove angle is 65°.

6. The welding method of claim 1, wherein, The interlayer temperature is 40-100 ℃.

7. The welding method of claim 6, wherein, The interlayer temperature is 45-100 ℃.

8. The welding method of claim 1, wherein, The welding material has a diameter of 3.2 mm.

9. The welding method of claim 1, wherein, The high manganese steel contains, in mass percentage, C: 0.35%-0.55%, Mn: 22%-26%, Si: 0.10%-0.50%, S: ≤0.01%, P: ≤0.03%, Ni: ≤2.50%, Cr: 3.0%-4.0%, Cu: 0.3%-0.7%, and the balance of Fe and inevitable impurity elements.

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